What is alg.exe? Is alg.exe spyware or a virus?

How to fix alg.exe related problems?
1. Run Security Task Manager to check your alg process
2. Run Windows Repair Tool to repair alg.exe related Windows Errors
3. Run MalwareBytes to remove persistent malware

Process name: Application Layer Gateway Service

Product: Windows

Company: Microsoft

File: alg.exe

Security Rating:

Application Layer Gateway service is a component of of Windows OS. It is required if you use a third-party firewall or Internet Connection Sharing (ICS) to connect to the internet. If you end this program using the Task Manager, you will lose all Internet connectivity until your next system restart or login. http://www.neuber.com/taskmanager/process/alg.exe.html 

Note: The alg.exe file is located in the folder C:\Windows\System32. In other cases, alg.exe is a virus, spyware, trojan or worm! Check this with Security Task Manager.

Click to Run a Free Scan for alg.exe related errors

Users Opinions

Average user rating of alg.exe: based on 493 votes. Read also the 415 reviews.

7935 users ask for this file. 202 users rated it as not dangerous. 37 users rated it as not so dangerous. 111 users rated it as neutral. 66 users rated it as little bit dangerous. 77 users rated it as dangerous. 44 users didn't rate it ("don't know").

All comments about alg.exe:
Application Layer Gateway Service   Alex
file is located in the c:\windows\System32 folder   nithin
Its an important program but can be linked with parasites   God
Application gateway layer  
when this application is active this cause to accure error while i want to close windows explorer or internet explorer.after terminating this task everything is ok.   nice fox
it's a microsoft based file.   Emrah
Description: Part of Internet Connection Sharing application and Internet Connection Firewall for Windows XP. This service provides support for third party protocol plug-ins for the Internet Connection Sharing application and Internet Connection Firewall.  See also: Link   gkalia
Knocked the damn thing off with aports.exe, don't see any problem, everything works fine   Lysander
ICS file no need to worry   eddie
it may legitimately be found in other folders on XP systems   Dorkster
ALG.exe means Application Layer Gateway Service. It's used for internet connection sharing. Stay cool.   Mariano
Known Spyware/Trojan. IT is known for its unique ability to reconfig your regestry...HS.Hack.34   McAfee Virus Tech
It is used by windows XP firewall... To prove it, go into your network properties and turn off your firewall. It will disapear from your task list. So if you want your firewall to work you had better leave it! (Dont forget to turn your firewall back on!)   Shane
It's Microsoft specific, required for XP SP2. NOT DANGEROUS. Not SpyWare/Trojan as some have said.  
you can disable it, but you will lose MS firewall (not big deal), Internet connection sharin. if u dont need it, disable it and save resources   marcofulvio
This item shows up in your process list in Windows XP if you turn on the personal firewall built into XP. You can look for firewall in windows help to learn how to turn it on and off.   DarkRider
Normally fine, but something changed mine to stop Norton from autoscan & email scanning capabilities.   Chris
since I applied microsoft firewall on my computer, als.exe is appear on backgound process. don't worry ,it's not harm   dadan_konsol
it's knocking off my explorer when i try to get this file's properties and i don't know why, that's why is suspect  
this archive bring me problems to play multimedia   KLEYDO
xp firewall is disabled and yet it still appeared.  
Useless crap from M$ that gets started even though you don't need or want it   Bob Gates
Till now I used to believe that it's creating trouble with the internet connection or something. So i always turn it off from the task manager. But now i learn that it;s a windows internal process. not sure really. could it be possible that alg.exe gets infexted with viruses easily. Or is it possible that alg.exe lets access to my PC or else lets some malicious program communicate with its server when i am connected to the internet.   ddas
alg.exe is located in "C:\WINNT\SYSTEM32\" on Windows 2000 and "C:\WINDOWS\SYSTEM32\" on Windows XP. If the file alg.exe is in other place, it could be a spyware, trojan, worm or virus!   zero
You can disable it if you have 3rd party Firewall.   james
The service is NOT dangerous; if you use other firewall than MS and you don't share printers, files or computer resources in a network you can disable the alg.exe service; however, if you do share your PC resources, leave this service alone cause you'll need it.e   Parsifal
when i setup my windows xp professional if any problem comes to me then i press ctrl+ alt+ del just iget taskmanger how can i found it which is the important file of operating system and then i press endtask   mdeshakhanonthenet
It appeared after WinXP SP2 was installed and their Firewall enabled. It stayed around after I stopped the firewall, and so I hit "End Process" in the task manager. No problems.   Andrew
Killing ALG.exe on WinXP SP2 doesn't stop internet working at all on my box. Agree is used by win f'wall.   Adrian
apparently alg.exe craps up several useful little tools like internet explorer. i'm having to kill it regularly to keep IE from crashing on me.   Gralgrathor
Came up immediately after installing XP SP2 - Seems to be for the XP firewall as others have reported   lasher62
Disable the xp firewall (if you don't need it) and it disappears. *shrug*   Kachiko
Pops up even if you disable XP Firewall !!! Rename it and it'll never come back (like msmsgr.exe)   OtherFox
what i know is i have it too..so no harm gus..don't worry   Aiman_AZmi
I know that Shane is WRONG...I disabled the firewall, restarted...it's still there   joe blow
appeared after run xp sp2 so I assume firewall process is the story behind it!   mtis2000
is more dangerous, it a trojan   Netanyahu
It is simply explain in Services. Go to Control Panel, double click Administrative Tools, double click Services. it's next to Alerter.   omega13
Whenever windows XP starts up this alg.exe LOCAL_HOST, I can no longer access the internet and need to reboot. Very irritating.   CS
located in c:\windows\system32; c:\windows\prefetch; c:\windows\servicepackfiles\i386; c:\windows\softwaredistribution\download\75e4029c35a8b37105984119f6cd14 all files sized 44kB.. internet works totally fine when alg.exe running.. lacks the guts to delete/end task   Canute
I know after installing servicepack Xp om my 600mhz ( with 500mb ram ) my computer got slower. i dont need it when i have tcp and udp control in my router..   T
Definatly used as a server by psrticulsr trojans and worms to relay back to other computers. \trust me, I just spent 3 hours cleaning it all up. It is a legt file but can be manipulated (e.g. svchost.exe)   Chris
Disabling the XP firewall doesn't always remove it. It certainly causes problems with explorer and my PC "freezes" for no reason on occasion when it is active.   Bredwell
ALG is a service which can be disabled in the Services MMC. It WILL NOT disrupt your internet connection. I am a Networking professional, Certified!   Doc
When I start up my computer, this alg.exe starts. When it's running, I can't connect to the internet. When I kill the process, internet works fine.   WhI$tTL£R
It appears as part of the Firewall in SP2. It's a service and can be disabled once you disable the Windows Firewall.   SD
It is part os XPsp2. To make it go away turn off "Windows Firewall/Internet Connection Sharing (ICS)"   BOFH
its an official MS file. you can look it up on their site, they have a process info page.   freaky
This is not a virus, It is a file with SP2 for the new firewall, and security centre.   Kevin H.
Neutral, Part of windows firewall, doesn't consume that much memory.   Sérgio Santos
zonealarm want't to block it, did it and everthing works fine :)   el_Loco
isn't bad at all...just with the new windows firewall.   jen
It is possibly a worm.  See also: Link   Ben Dover
siksok bisey iste   alomelo
 See also: Link   kaleos
according to Symantec, may be part of the W32.Petch virus, which is extremely dangerous.  See also: Link   Frank Ross
Came with XP SP2 and claims to be needed for 3rd party firewall operation as well as IC sharing. Apparently before sp2 my IC and firewall were working fine without alg.exe service listening on the background.   Renokan
it loads with outpost, as it was told on this site  See also: Link   NickiSpeaki
Has to do with the Internet Connection Firewall, but about 5 minutes after I enabled the firewall, Norton told me I had a worm on my computer.   Gary
i got infected with this alg.exe by visiting a website. it disabled my virus scan's internet filter. very tricky. Someone help me! i just rebiult my computer yesterday   Evan
tried to contact ftpmysite.verizon.net. It is located in c:\windows\system32...seems to be a trojan   newHere
Windows file!! like any other windows file, not dangerous in case you keep your windows updated.   Mohamed Elnamaky
The file *can* be a trojan but often isn't. You don't just disable the firewall to get rid of it. You have to stop the process from starting at startup, try the registry or msconfig program. It is *not* always a trojan and it is not useless M$ crap. If you don't like MS run linux.   Better than "McAffee spyware tech" fool
alg.exe keeps port 1033 open (Netspy trojan port). Netspy is a relatively rare, however extremely powerful trojan.   AOL tech (fun stuff)
it starts even if windows firwall is diabled. Go to Control Panel, double click Administrative Tools, double click Services. disable and stop.   fugedabowdit
My explorer crashes while alg.exe is running. Disabeling it like omega13 described solved my problem, and freed 600k of memory. WOHOO!   Gyner
Just freaking go to run and type services.msc Now go to the Application Layer Gateway Servie properties. Now stop it and then select "Disabled" for startup type. Now it's gone and will never run again. Renaming files is not EVER the best solution, errors could occur if the file is not found. Diable it the correct way.   Hank Hill
I read that if you disabled the firewall, and had ICS off, that ALG would not run. Well, both are disabled and it's still running. I'm suspecting it to be the source for some of my connection problems elsewhere...   Johnboy722
I found alg.exe in three different folders. I disabled them all, but the file in the System 32 folder and I regained control of my Internet Explorer. I am not sure it is completely legit. Looks like it depends on its location.   ELEGANCE
i tried to delete a folder, but i wasn't able to do this until i terminated this task.   juna
If you don't share anything or use MS firewall, get rid of it.   John
DUH!!! Trun off your firewall and see what happens. This is an ICS related program and is Neccasary if you want to use windows firewall.   Rebber
Provides support for 3rd party protocol plug-ins for Internet Connection Sharing and the Windows Firewall.   ??
it supports 3rd party protocol plug-ins for internet connection sharing and windows firewall   Absolute
This file is also under SP1 But it's unstable on SP1(a) XP comps. Use alg on SP2 only.   Sn0WDr4gon
Application Layer Gateway service is a component of Windows OS   Someone
the original purpose is 1 of 2 things.... windows run firewall, or ICS (internet connection sharing).. so you can disable the whole service package under controlpanel/admistrative tools/services"windowsfirewall/ICS" if you have your own firewall and an external router. if you are using windows firewall or are using the machin as an internet gateway for other machines, then leave it on. it is possible it could become corrupted, never seen it in the wild though   Delta-9
Ben Dover is wrong. On his link it is said that some internet worm DELETES alg.exe. This surely does not mean that alg is a worm. Of course it is possible that a parasite can have any name, including alg.exe, but Ben's link shows no evidence of that.   marginal
If you have a firewall you can turn ALG off in the "services.msc" in the run command. Though only turn off stuff that you know you don't need. Turn the wrong stuff off and you'll have to reinstall OS from scratch.   leviathan
disabled by zone alarm,noticed nothing wrong   fonito
it's in 3 different locations "C:\windows\$ntservicepackuninstall$" "C:\windows\system32" "C:\windows\servicepackfiles\i386" also the one under uninstall folder is smaller in size   bean
Oh, that was WinXP home btw...and you can just goto control panel--open admin tools--services--and stop the program/restart the program   bean
i have SP2 and this file is both in c:\windows\system32 and C:\windows\ServicePackFiles\i386 .is there any threat of virus here? thanks   Arian
yeah its microsoft maybe but tends to lock the workstation, when i kill it all seems to revive so if you have other firewall local or on your LAN kill it 4 goot and you will not regret :)   Jur
i dont kwno why everyoen says sp2 i dont have sp2 and its on my system, could be cause i have aol put on and i dont think i noticed it before   gerald
FOR BRAZILIANS: não sei o que ele é realmente. Mas acaba trazendo alguns erros, por exemplo em jogos que ocupam memória 3D ele os diexa mais lentos   INTERNET SECURITY CENTER BRAZIL
A firewall integrated in XP   Roberto
it sux... it slows my internet down.. f**king M$...  
This file is also in SP1 machines. It is not specific to SP2. I use ICS so I have the file running. No problems here at all.   TuT
Seems like there is some Spy-ware with this name too! 2 are legit (c:/windows/system32 and in the updates folder, both dated 08/2004 and 44KB. The mean one 's got 16KB and is in a different folder. Deleted it, restarted, and everything worked fine again with the genuine ones.   Georg
seems to be associated with spyware on my pc. The time I see it running when I'm getting pop ups and such.  
I'm on a LAN running DSL. I end the process while downloading a file from the internet, nothing happened. I do know it popped up after installing dangerous Active X controls which did have a crap load of spyware and junk in it. So take it how you want it.   aR6guy
If u pc share internet connection, windows xp need this aplication to run, now in my language ;) Si tu pc comparte conexion a internet necesita tener cargado ALG.EXE  
Knocked down my IC, I could ping ip-s in the outside, but win wasn't able to get the ip-s for the www adresses from the dns server. I killed the process, everything works fine.   mutra
It is necessary.Do NOT end it..   Turker
Its common if you run McAfee firewall   Noreaga
Microsoft application  See also: Link   Benji
i know as a good senior computer user that it is a trojan !! please read everything on the link and it will prove that it is what it is.the creators webside of the trojan is offline so in fact its no longer harmfull ((i think)) its easy to delete just click on search file. its not from microsoft system or any updates!!!  See also: Link   Alex Raptor
This is just the Windows Firewall/Internet Connection Sharing (ICS).  See also: Link   zionid
Its not a dangerous file, but uses resources anyway. It exists also in compressed Service pack files and uninstall folder of service pack. If you see it in a weird folder, it might be suspicious. If you dont use Windows Firewall and if you dont share your internet connection, you can disable it. It can be disabled and stopped from local Services (Administrative Tools) -or as it explained here many times- by Start (button) Run (typing) services.msc . It is the 2nd service from the top (after Alerter). Double click on it, "Stop" the service, and change the "Startup Type" to "Disabled". Click ok.   ilteractive
it floods the ram when using file sharing program ie DC++   Odd Hermit
This file suck. After I connect trough Dial-Up to Internet all connectivity stops after 5 minutes. If I shut down from Taskmngr alg.exe everything is OK.   Fade2black
some time this alg.exe hanging up my internet connection i i need to kill this task in order to have inet connectivity   Valentas
alg.exe is a 40Kb file - a potential windows exploit. It opens a port allowing your system to be vulnerable with potential of full exploitation. Sp1or2 has this window component. ICF/ICS allowing Windows firewall and third party plug ins and perhaps alteration to the firewall. Disabled, I find no current issues. It may be re-enabled via the internet if your system is vulnerable. Very Wairy!!!   Mr. TC
same as listed originally, If your behind a firewall router, you dont need this exe taking up cpu cycles.   John
Had an outside port connection to it, no alg.exe file was found on my hdd. It was killed through task manager. I recently started windows firewall but there's NO reason it should have a live connection like that. Very bad.  
system process   jj
My connection was boosted 50% after i terminated this one.   Boris
Application Layer Gateway Service (Alg.exe) Windows Firewall/Internet Connection Sharing (ICS) component  See also: Link   crae
If you don't need the firewall and ics, you can disable the service "Windows-Firewall/Gemeinsame Nutzung der Internetverbindung" and it disappears.   Joe
I think its somehow linked to spyware or a virus. Since i installed Divxtrailbundle, which is ment to have the gain spyware, the Alg.exe is trying to connect to the net ( according to norton firewall -in pro-config-). But you will never see it connect unless you turn all blocking options on ( external moduls check.....and programm launch monitoring ) I never used the windows firewall.   JUDAS
fresh install with sp2 slipstreamed, after a hour online sygate came up asking if i wanted to let alg.exe ftp out to such-and-such address and thats with xp firewall off and no ics on this puter, did a search and found it only in the /system32 folder, you tell me, if it was a needed program why is it trying to ftp out to a non microsoft ip? for that matter why is it trying to ftp out at all?  
Malware authors have used this exe name. Tracking back from firewall logs led me to three owned laptops with non-system32 directories alg.exe's running as the top process while tcpdump showed the laptops busily trying to audit netbios shares....don't nuke out of hand..there is a real alg.exe...but don't assume that it's presence in a ill machine's process stack is 'good'. My advice...if you see it as your top process start tcpdumping the traffic from that machine, even if it's the legit alg.exe, at best something is pestering that station's firewall   Another BOFH
What i know is that most of you seem to thrive on gossip. maintain good antivirus ( this means updating more then once a year :) ) use a good malware detector periodically ( i wont mention names as that seems to open can of worms here and Above all use common sense. You only get infected if you are lax in prevention. in conclusion ANY file could in theory be harmful as you can rename them anythign you want windows doesnt really care. Most infections i encounter are due to lack of knowledge on machine owners part and by uninformed people who want to download "HACKS" of various types peace   Wildman
can't go to any sites or use internet, i killed and things start working again   beef stu
Windows System Process for Internet Connection Sharing  See also: Link   Nathalie Oldenburg
well it blocks all connections to internet that what i m experiencing   suleyman
just when the windows start it is executing as i see in the task manager and my floppy drive and cd drive as getting accessed unnecessarily and when i end the process they DONT......   shakeel
There is a worm connected to this that is a file called W32.Petch. If executed it can change your registry & delete system files. I did a search on alg.exe, found your site here, then went to Symantec and read about it & am trying to do a scan to find it. It must be what's screwed up my antivirus that isn't working this a.m.   Jackie
It can be configured in firewalls not to access internet and still work. I have it blocked full time and i can still dial up and connect etc.   Troy or Eva
It is a normal process, not harmful. Should your Firewall detect access to this file, block it, and you won't have any troubles with it.   Dan
It appears to bring stability back into my system by disabling/stopping it. Of course, we do have other firewall protections... however of note, the false statements listed above COULD have been by those that enjoy exploiting it's weaknesses. Not to mention find people that only lightly understand this arena; therefore, I suggest maximum caution when giving away personal information..such as your email addy which could contain your DOMAIN......might as well advertise that you don't lock your house and oh, btw, take down my address, stranger.   PredatorHunter
why does it want to connect to port 4777   John Purdue
Windows still launches alg.exe even if 3rd party firewall is being used. Suggest disable alg.exe in services (See Hank Hill Post Above) When running alg.exe system can be compromised real-time all the way down to CMOS   racerdog
This file only apears in TaskManager for me when sharing my internet conection. If you have any doubts, and are not using a firewall or sharing a conection, I would look into turning off *Remote desktop, *Error reporting, and *File sharing of ANY kind. Hold windows key and tap Pause/Break button for System Properties to appear. ETC.   1541 SID
I found this process running and using a program what’s running. It located it with an open port 1029, under ip connections and the name of a computer attached to my workgroup running this file was called toolbarpartner.com, not part of my workgroup, seem like a Trojan to me. I ended the process no problems with internet connection.  See also: Link   Tomg802
The darn wast of RAM isn;t needed for 3rd party firewalls. I use Zone Alarm, and don't run the program.   RLS0812
Before the installation of Service Pack 2, this service was required for use with the Windows Firewall/Internet Connection Sharing * service. After the installation of Service Pack 2, it no longer is required. No Dependencies.   RCAdmin
My PC just freezes, monitor goes black and I have to restart. Without this thing running, everything is fine. Maybe it is not compatible with some other applications running in the background.   Seppel
Using NS Auditor, its in the system32 folder on XP and listens on 1035 Its flagged as; " Multidropper" Must be an exploitable MS service associated with MS firewall. Administrative Tools, and ZA blocking should help. There appears to be a lot of processes that attempt to , bypass and disable firewalls, and antispyware. Deserves a closer look!   Geebee
Its a windows file, that can easily be comprimised by a virus or other malicious program   God
Using NS Auditor, its in the system32 folder on XP and is listens on  
Lysander get rid of aports.exe. An API is available for this application, which can be used in malicious code.   marksu
some spywares are hiding on my OS and using this executable file thru internet. I found something strange when I updated my third party firewall and also my XP Professional to SP2...when I restart the pc my firewall ask me about some previous services allowed to go outside that might be changed recently..then I realize that the alg.exe is't working proprely since the firewall was alarming attempts to go by ftp outside using this file.   Marcelo, São Paulo,Brazil
It knocks me off the damn internet!! I Disable it! I be online for a few minutes, then loses connection, I disable it in Task Manager, and I stay online. Even with updates, ALG.EXE boots me off!   lawnmowerdudeintexas
It's part of the windows OS. Anything in the windows OS can succumb to a virus.   Zeon
If you do not share internet connection do not use it, I disabled mine.   Invetero
do not Disable or Remove "alg.exe" if you are using a "Linksys Wireless-G Portable USB Adapter" (model #: WUSB54GP). According to Linksys, Win XP cannot detect wireless networks through the adapter if the ALG isn’t running. You’ll have to rely on a 3rd party connection assistant, and don’t count on the Linksys connection assistant either.  See also: Link   Cold Titan
Application Layer Gateway used for Internet Connection Sharing - not dangerous in any way   nat
If you don't allow other computers to connect to yours, especially if you have a permanent internet connection, you can go into the firewall settings and click "allow no exceptions" to disable any outside connection to your computer. Then, you can disable alg.exe if you wish as described by others here. Windows firewall doesn't need it. My router logs showed alot of traffic to ports 1026 1027 10000, to an inactive machine, and I ran "netstat -ano" which showed established connections on 1026 &1027, with the pid of alg.exe. In a case like that, it's OK to kill. But it's needed for ICS.  See also: Link   acerimusdux
I delete this file on every computer i have. it is a useless program. ctrl-alt-del look at processes and stop it. go to windows explorer, search for it and delete it while you are in windows task manager look at all the processes that are running, most are useless. go to this web page and sort through what you have http://www.sysinfo.org/startupinfo.html shutdown what you dont need and find files on computer and delete them. Run hijackthis.exe and it will also show you what you have running and a process to stop unneeded programs from running.   Robert Stone
The alg.exe is used by application layer gateway. However, if you have a shared internet connection (internet gateway in network connections) check the TCP and UDP ports that are in use. I normally keep track of strange, unwanted access through ports I didn't set up. on my computer the msmsg service was using a lot of ports above th 1024 range.) I find that very suspicious. Or am I wrong here?   Marcel D
i have my own hw firewall with few opened port on tcp/udp. *** while every non-os app was shutted down, alg.exe was sending/receiving pc packets from some odds ip (some of them listed in Spamhaus_Block_List). *** -- so i think it's dangerous when not needed (essential ONLY for XP firewall). **** i removed it and still navigating great! *** cheers!   piniz
A part of the Windows XP internet connection wizard. Only required if you use internet connection sharing, but it's often used as a 'false negative' by virus writers. If this pops up without any direct cause, try closing it; in the worst case scenario, you'll lose internet connectivity until a reboot.   Theogrin
I have this file running linked with Redwood Broker. Which means someone has injected a scanner into my computer. Still its in the right place, system 32. Found it going through the processes one by one in my firewall-log. The link shows what hides behind the process.  See also: Link   Twohigh
its only good fof comercial stuff.safe youre cpu resources and just shut it down,go to start,get property on my computer by right click on it,select manage then select services then disable aplication gateway service (alg),and it wil not be any problem any more   pascal
Malicious download installed Perfect Keylogger (invisible but runs file msservr.exe visible in Task Manager) to send logged keystrokes via the Application Layer Gateway (Alg.exe) so it can be used by trojans but is a legitimate but vulnerable process   Cal Kup
Windows component. app, layer gateway service. Used in internet connection sharing and firewall. Not a threat in itsself but can be replaced/infected by trojans/virus' (just like any other .exe)  
"Do not end this program in task manager - you will lose all internet connectivity until next restart or login." I shut it down in Task Manager with no prob. Win XP PRO   SuM Beach66
I could not find any suspicous files in any of my 4 spyware scanners while alg.exe was running so I don't think that there is anything wrong   mesa
I have had this service disabled on my XP home system for a good long time. Am using ZoneAlarm Free and it surfs real good.   toon-hed
Did somebody speak to me? The voices in my head are telling me to Delete all running tasks and go Moose & Seal hunting!   Alter Walter
It's a windows file. Anyone else saying otherwise is either retarded or is trying to get you to damge your computer.   Common Sense
If you found it in "windows\system32", leave it alone, otherwise delete it   Anubys
Naaja. Es mag ja sein, das alg.exe ein legit Prozess sein mag, aaaber: "Before the installation of Service Pack 2, this service was required for use with the Windows Firewall/Internet Connection Sharing * service. After the installation of Service Pack 2, it no longer is required." Das glaub ich allerdings auch. Denn MEINE nagelneue WinXP Installation hat in den ersten Tagen wunderbar gefunzt, was Systemauslastung und Verbindungsgeschwindigkeit anging. Doch seit ein paar Tagen war der Wurm drinne. z.B. mp3-Wiedergabe manchmal sehr verstottert, v.a. wenn grössere Seiten abgerufen wurden.....   phluxx
Most of the time, this is part of Windows Firewall and required for XP SP2 (that means you shouldn't remove it.) People say they saw no difference when they removed it--that's just because they turned off all their security. You can disable it, but no one will give you any sympathy when you get hacked. This can also be the name of a virus/spyware process, which you'll have to search on google for help removing.  See also: Link   Colin Jensen
When your using xp firewall leave it on! If you want to turn it off , like me it does not turn off . so Run services.msc and properties on Windows Firewall/Internet Connection Sharing (ICS) stop it and inactivate it. Doing so you have no firewall true xp. (using norton my self)   Uneek
This process is garbage if you use a 3rd party firewall and don't need windows garbage firewall. This program provides optional utilities like the Windows Firewall and ICS. If you're not using either one of them then you should not be seeing this program run.  See also: Link   Dice
It's a hideous new type of Root Kit-based Trojan Hologram, that will silently erase everything in memory - not the computer's, but YOUR memory. You won't be able to remember a thing after a few, brief seconds. Now, what was I talking about, again?   Dirk Dingwall
The information above says closing the program will disable internet connectivity. I disabled my copy of ALG.EXE prior to opening my browswer and am having no problems on the internet so far. I use Cable HIgh speed, Zonealarm, and Mozilla.  
after i end this in task manager i get several trojans blocked alerts from norton internet security. when it was running, i didnt get any so i have disabled it completely now from control panel / system /administrative services   sheep
When it is loaded, it stops me from being able to open .exe files. Probably in combinatie with a trojan. When I deleted alg.exe (also from registry) I was able to open .exe files again   Urk
The file "alg.exe" appears AFTER the installation of the Canon-i865-printer. Before you installed the printer alg wasn`t activated. Well, however, closing alg.exe couldn`t be bad.   cold
Well it used some of my files comletely at random: I couldn't move those files before terminating ALG.EXE. Even if I made copies, those copies couldn't be moved/deleted :P weird   sIG
I've killed the task "alg.exe", and the internet connection was not locked. Ich habe den task "alg.exe" beended, die Internetverbindung aller Programme blieb jedoch erhalten.  
What if you find it in Service Pack Files? There's two instances of it on this machine. And if it's a trojan or other virus of some sort, how do I get rid of it?   Neko
Tryed it once. Did a good job of closing down unwanted programs. What I need is a way to load with mim of programs, as I have a machine I use only TO WRITE ON.  
I end the process as soon as I log on. It never comes back. and doesn't give any problem at all when I go online. Disable Windows firewall and use ZoneAlarm.   Rose
Application Layer Gateway is all I know. I am using Zone Alarm, and this file wants to access the internet. Should I let it or deny it?   Scott
I keep finding files that people say should only be in a system directory in C:\WINDOWS\prefetch is this normal?  
This process can interfere with P2P network connections. If you use ICS leave it running otherwise kill it.   Mike
ZA traps alg.exe trying to FTP out to an IP (example: I disabled alg.exe from services.msc.   japh Cheesehead
Allows dial up connections to be seen over a lan. it dosent look very dangerous from outside a lan.   mandai
fricken annoying file, stoped my internet from working untill i deleted it fully through regedit  
harmless have end tasked it many times and have not lost internet until next reboot   sparklewoof
Killed the Task and wiped it off the System32 Folder, no problems here (WinXPsp2)   PhunkyData
I turned Windows firewall off and I got 60 second shutdown LSA shell error crap.   Malus
causes every program i run to crash, if turned off, everything works fine   annoyed person
all i know is that file is running also as a service in windows   Mohammed Yehia
it ate my lunch! When I came back my sandwich was gone!   Sam
This file is a threat to democracy and the American way  See also: Link   Joe Citizen
It's a system Process... absolutely no danger!  
Microsoft files not always safe   ???
Er fährt das Sysem herunter. It shuts down the System!   Ivan
It is for FTP connections and Downloading Data -- use a event firewall to accept or not this file to communicate when it need ! :)   Dr.Stub
Some people say that file is a spyware include by Microsoft. So, be careful !!   Garfield
i stopped it and still have a connection and don't have sp2   whizzy
If you dont use windows implemented internet sharing or firewall , you can safely turn this service off.   Franta Krepelka
As said before it is a legit file from microsoft, but it can be replaced by trojan/virus if your computer is working fine with it there leave it alone, but if you are having problens with your computer and you are not using the windows firewall, but it is still in processes, remove it   Zumbi
Standard Ms WinXP file, is active when XP Firewall is activated. Please check location, it should be: "C:\WINNT\SYSTEM32\", otherwise it's mallicious! Exchanges some information with Ms servers. No big deal! If you have an other Personal Firewall ( SW) or hardware Firewall, you can stop this service or limit bandtwith of this service with DU_Supercontroller.   CJLABS.be/
Linked to Windows Firewall, Bothering, but not dangerous. Windows keeps it running even if you use third party Firewall software   Jesper
Standard Windows Datei   SCORPiON
In \windows\system32 it's a windows component. If you find it anywhere else it may be a trojan or virus.   Aspegic
Used by windows xp firewall   Omid Gulban
Included Wint Windows XP Firewall   Sklawz
Ok Marcelo is right if you disable this you will not be able to connect to ftp's ........ it is not dangerous but it can be used in ways you dont want eg trojons, keyloggers ect .... disable this will not have ill effects but remember it disables ftp.......i donno about the windows firewall thing ZoneAlarm is better on my comp :p ....   JK
I've been a software developer for a dozen years. This is the first time I ever noticed ALG.EXE in task manager. I just installed "AOL 9.0 Security Edition" about 2 weeks ago. Maybe it came from that??   Mark
Running process in winxp sp2 even after disabling firewall...managed to disable the application layer gateway in admintools services to get rid of it and make my connection better   M
this program is not dangerous, helps the internet work properly, dont disable it   Robbie
ALG generally serves as a proxy for incomming transport layer data ( external communication ) Leave it on, unless you like a synner.   macadrone
You don't need this file for internet connection. This file is running even if you turn off the firewall. This file shows up when I temporarily turn off the firewall. Why? Because an unwanted background spamming shit is being linked to it. I deleted it (you have to fool XP file protection of course).   DoG
if this prozess runs with priority 'normal' any other web-tool won't run (firefox, icq, ...), it only works if I set the process priority to a lower level   dark7even
Systemfile Windows - Application Layer Gateway Service   FI-Schalter
Well, if you do end task it, it sure doesn't end internet connections while using Firefox, and also, it doesn't go away disabling Windows firewall. It has funny ways with ports, however, get a good hardware firewall and don't sweat it. Back up your $hyT, kids. Always handy.   Kyle Weiss
When I right-click, the menu pops up very slow. After I disable alg.exe, it's normal again.   Lone Wolf
It´s required for ftp.exe, because ftp.exe connect to alg.exe and then alg.exe connect to ftp server. In antivirus rules is needed that alg.exe pass.   Alex Gamboa
this damn process .. can be easily modified   binesh
my internet explorer was hanging at the first use.i tried several things it dint work.at last i killed this process alg.exe it worked fine.   Venoy
The fact that it might be of help for XP Firewall and ICS doesn't mean (at least for me) to not terminate it. CUZ first, I use a non-XP/built-in firewall but ZA, second, I don't use Internet Connection Sharing, third, IT USALLY ACTS AS A SERVER!!! I've terminated it for several sessions and I believe my net send&receive loads are now more regulated and refined. Anyway, my advice might only be of use for people with similar conditions as mine.   Sadegh Sheikh
that file freeze my pc   barmes
Spyware made by microsoft.com   Spywarehater
it is important file but should verify that it is not a virus   subodh
i squished a bug today  See also: Link   boogadiboo
I just killed it and my internet still works fine.   yamaha356
I use 3rd Party Firewall and share a Printer - everyone goes to the Internet through a Linksys Hub. I let Zonealarm Deny this bastard any connectivity as it is possibly a leech on my system   Death to Spyware Developers
If it is in the System32 file its ok, Delete any other version of it   Rob
When I turned this off in the task manager I stopped having problems with one of my games. What use is it otherwise?  
It sends many MB to the Internet. It was up to 30MB when I noticed it. I stopped the process. All is well now and the traffic from my computer to the Internet (who knows where to) is down ot thew bytes sent for requests.   Allaoua Cheraitia
It is located on my computer in C:\i386 amongst a bunch of inciminating spyware/trojan style stuff. I found pictures of other ppls computer(screenshots), pictures of people sitting on computers, regedit, keystroke logger, and a bunch of stuff that looked like it was stolen off of anothers computer. it was a separate instance from the one running in system and is a little smaller(41k)  
Flagged by Kaspersky anti hacker when specific macine ids attempt to access my system. blocking inbound activity has had no negetive effect.   topgun
alg.exe is a part of the Win XP OS. ALG means Application Layer Gateway Service. This is a core process for microsoft internet connection sharing & firewall. That being said, it should not be terminated.   Mechpaladin (Vernon Chan)
Used to allow software firewalls (ZA,Norton) as well as XP firewall to operate and works with ICS too. While a virus could overwrite this file or delete and run as, your AV should notice this(you do have one right?) Only disable if you are behind hardware firewall or not using any firewall at all (you really like to be infected with viruses don't you)   Zeno
3rd party firewall (firewall other than your OS firewall)   rice addict
Required components for Windows Firewall and Internet Connection Sharing,,Key binary - alg.exe, hnetcfg.dll, hnetcfg.mof, ip6fw.sys, netfw.inf .   xpsp2 rox
If you don't want it to run as a background servicethen just disable it in services - If you have problems, then just revert it to it's initial state before u changed it!   Chugnut
This file allows access to your computer from other puters on the net. See keystroke logging and computor monitoring software. Remote desktop software in XP.   Firefox 06
Does Not work well with Java apps in IE   Timothy R. Linde (TimeLord)
I got rid of this file and my network connection works well ...  
Internet Connectionsharing   MB
I had problems with 'unknown' programs using ALG.EXE to FTP out. I have disabled the ALG service and stopped it. FTP works fine. I have Windows SP2 and SPF (last version) with Windows Firewall enabled.   Haplo
If you cannot connect to ftp's reinstall the program or reset it thru Command.com or CMD.exe.   Kent
It appears to be a registered task that links with IE, but can be tied in with parasites  
I couldnt access yahoo games,torrent clients,webcam connecting stuff etc even if my firewall exepted them,even with firewall off.was sweating for days&nobody could tell me why i can't access these things I was initially able to.meanwhile i found some trojan in my comp (in system volume restore)which was removed but i still had this problem with access to applets etc. then when i was ready to reinstall my windows as the only sad perspective,i found this darn process in my task manager.once i removed it, everything ran normal.it's in system32 but its a dang trojan,be careful! :(   Petja
Some Prog use this as back door to phone home. If you have a REAL fire-wall, showing you ALL out going requests   MFEM MFEMFE
File used by Windows XP Firewall   Peter Mumo
go to start run type Services.msc ok look for Windows Firewall double click under Startup Type click Disabled then click Stop to remove from Process list. NOTE: only applie to those with a 3rd-party Firewall installed already!   Maur
It is acctually essential if you use ICS - Internet Connection Sharing. Without it, some elements on the other users' computers will not work properly.   go2hell
open to abuse. sometimes communicates with Boddah's-ultra file sharing portal ( More spyware people. Want access to put third party garbage in machine.   alex
A Windows file that tries to hijack my firefox. Deny access and internet connection doesn't work.  
This file use for ICS   Majid
You can disable it even if your PC is hosting the ICS. No problems there, other clients are still able to connect to the internet through you.   Javewa
I have got AVG Anti-Virus and everytime my machine starts it says alg.exe is infected. Even if I "Heal" it, the same thing happens next time. And it creates hell lot number of IExplorer.exe instances in memory. Please help me out of this.   Milind
Everytime I end the alg.exe process. This makes my machine much faster and better. There is no chance of loosing the internet connectivity if we end the process... It is working fine,,   Daya Anand
it is part of the windows firewall  
some programs may use it (carom3d), if the program crashes killing/restarting the process *can* help   mike
it is a microsoft file (biggest threat to your computer) a target for malware producers. turn it off and get zone alarm full version (pay for good protection) a prog like spybot sd can tell you what modules it is running so you can kill them and not lose the file. crap like nail adds a module to an existing exe thet spawns the malwares own exe's, nail hits print spooler. if the module is killed the exe is fine. ps i have killed nail by hand so i know   the man who don't trust pros
i found this along with other trojan related processes...i can vouch for what someone said about it messing with norton, i had multiple trojans and norton could do nothing to get rid of them, though it did detect the other trojans.   shock312
Core part of the Microsoft Windows Operating System for Internet Connectivity ;)  See also: Link   Kisara
all you people saying that this is the problem when you end it everything works fine well it may not be alg.exe by itself it could have been corrupted but it is not a trojen it is not a virus i have never had any of the problems you guys speak of(oh and the guy calling himself mcfee virus tech....dude think of a better name than that mcfee blows even if you really are a tech there i wouldnt go around telling people that)   Lucky
It has applications in XP, should apply the philosophy "If its not broken, don't fix it"   AlphaViper
no problems with terminating the task, connection remains untouched (im posting with alg.exe off)   Smirnoff
its block my internet when it is running.so i have to shut it down manually.then the net works fine. can somebody tell me how to remove it ?   Rahul
When Active, It hogged 99% of my AMD3200+ CPU Virtually disabling my computer.   Pissed Off
If you have picked up spyware there's a good chance your alg.exe has been changed to a trojan downloader disable in if it trys to FTP out to IP address you don't know.  
Its File which you need to add into the Firewall to access FTP sites if you are not able to access .   Ravi chandra
it is part of the windows firewall and is safe to have running   itisme
alg.exe is located in "C:\WINNT\SYSTEM32\" on Windows 2000 and "C:\WINDOWS\SYSTEM32\" on Windows XP. If the file alg.exe is in other place, it could be a spyware, trojan, worm or virus!  
Since disabling alg.exe, transfers to clicked links in web pages is much faster - almost no delay. Also, my FTP connections to my web servers is much faster indeed. I've experienced no problems at all with it disabled, only good. My advice would be give it a try - you can always enable it again if needed.   Rinkidink
I disabled this process using the control panel an security center (it is windows firewall) but it comes back in task manager. I then went into control panel and administrative tools and disabled it in the services folder(application layer gateway).I had no problem after that.   catalac
Its an microsoft based file, usually connects with the ftp server, if you block this file through any firewall program you are not able to connect to ftp (file transfer protocol)   Ammar
i use internet ove network. it works around 30 min and then i lost the internet untill i restart the computer ill get it back.   Tarek Merhebi
this file make my connection worse   jeylan
It attached itself to my FTP processes. I never even saw it as I use Spygate firewall. The other day, it pooped up when I went to FTP and if I disable it, I cannot FTP.   Pheonix
It's at trusty application, is a service for Lan- internet gateway ! Application Layer Gateway!   UnderSky
i stop it after an error message appear "windows services.exe" or somthing like that, i stop this service and now my internet connection is fine. Probably a bug or connection stopper in xp sp2   hate disconnection
Application Layer Gateway Service   ms
I found this vie ZoneAlarm firewall. I trust this software.   Jingle Bells
you will *NOT* lose all internet connectivity if you stop this process!   jinn
Bog-standard XP component; No known vulnerabilities, but could be spoofed, of course  
I am running Vista Ultimate and Windows XP on a shared connection. The XP computer hasnt even installed service pack 2 yet i am getting this file. I believe alg.exe to be a monitoring device to police our downloads and sniff our systems. You dont need it and yeh im running norton as well and it messes with that. If you trust Microsoft you are a fool.   Peresium
It is the Application Layer Gateway Service.  
alg.exe is a part of the Microsoft Windows operating system. It is a core process for Microsoft Windows Internet Connection sharing and Internet connection firewall. This program is important for the stable and secure running of your computer and should not be terminated   Pres
Using internet connection   Vijay Masih
It's part of windows inbuild firewall, in XP if you are not using the windows firewall you can kill this safely will no ill effects and the net connectivity will still work (at least mine does). Can sometimes be a big target for trojan replacement files, malware and spyware too. Best to protect with a 3rd party fairewall and kill windows firewall and this process.   Sev
When I end alg.exe, it seems to effect my AVG E-Mail Scanner, why is this? AM I correct, or is there another problem?   Pierce
Alg.exe becomes active when your Windows firewall is turned on   Michael
many new ms aplications (IE7 / Messenger Live) require alg runing and not blocked by firewalls in ICS or under routers connections   emprear
ALG is a service which can be disabled in the Services.msc but if u dont have a firewall don't try it, it will hamper in the way of ur explorer   dragon4
Not dangerous, required for firewalls like noro  
this process is required for the 3rd party firewall.   Anuj
I use Intel Pro/Set Wireless for a wireless connection, and without this process running, I lose all internet.   OhSoCareful
On a windows XP system, the worm msrv32.exe hides itself within WINDOWS\System32\ and hijacks your internet. It creates a service by the name of 'Application Layer Gateway' and can easily be mistaken for this legit service. (Explanation: Its missing the word 'Service' in the description name.)   James
The file is needed for you to access the internet. It's pretty harmless.   Vivi
i always end this process as it i find it annoying in task manager and i still have internet connectivity this websites definition is wrong!   mattie_boi
Alg.exe can be terminated to run and have no adverse effects. Run msconfi go to services and untick it, I still have M S firewall running and all is well with the world   Tio Sam
ALG is the firewall support at application level. The one that provide firewall support per application in addition to standard firewall IP, protocol and port blocking. It is required and automatically activated and deactivated by the Windows firewall. If you use third party firewall, just disable the Windows firewall and the ALG won't be activated. Otherwise it is important in order to provide basic firewall for your system.   XT-Man
 See also: Link  
It's a system file, only virus/spyware if not in C:\WINDOWS\system32 folder,  See also: Link   Microsoft Corporation
I use 3rd party firewall so stopped and then disabled the "Application Layer Gateway Service" with no problems!Internet still works fine!   Chlodwing IV
When i saw this file, i tried to delete it, but every time i deleted it came back.   Stayer
I block it with 3rd party firewall. nothing bad   adam
its nearly harmless. you can switch it off in your services, you can block it in your Non-Win-Firewall and your machine will still run.   scHniefcHen
This is not necessary for the basic functioning of Windows Firewall after SP2.. Maybe for ICS.   Eric L
Windows OneCare Firewall asks to allow Internet access. This occurred for the first time about an hour after I configured my printer for Internet Sharing. No idea whether that caused this request. I always see Alg.exe running in the process list, but this is the first time it asked for Internet access.   Aeneas
My computer game would minimize then lock, only fix was a restart. I removed alg.exe and the problem has not come back.   rob
As long as you have at least Software DEP set to ON (on by default in XP Home and Pro SP2 - leave it on, mostly, only grant DEP off-permission on case by case basis, which is really rare and programmatically NEVER necessary to have DEP off) then alg.exe (all lower case) in Windows\system32\ AND NOWHERE ELSE, you will be fine. DLETE any other copy or occurance of it (except it may be in i386 folder if that is still on your computer after an XP installation).   clcradiogm
This file is not necessary for internet connection! It accesses some strange IP addresses.  
this program is not dangerous, helps the internet work properly, dont disable it ,If you want to turn it off , like me it does not turn off . so Run services.msc and properties on Windows Firewall/Internet Connection Sharing (ICS) stop it and inactivate it.   amit
used with Internet Connection Sharing and network bridges. If I disable, no ICS and no network bridge.   Argulion
It's attached to windows firewall but reports your personal information back to Microsoft.   Despina
Wanted server rights after installing itunes 7.4.2...... No way!... It may be legit but obviously 3rd parties can manipulate it....who knows who else? I don't run WinXP firewall and computer works fine without it...I did end task as well as disallow server rights. Also remember task manager in WinXP won't let you terminate critical system processes...no trouble terminating this one!   Mezzo
It's not a virus or trojan like some people are saying here. It's not a necessary part of the Windows Firewall as I've had it disabled for years. Some may need it if they use 3rd party ICF addons or use ICS (internet connection sharing).   Mike
Microsofts apllication layer gateway. Runs if you have windows built in firewall enabled. IT is NOT a TROJAN   kiLLaPriest
Microsoft Process. Totally not dangerous.   Cookie Monster
There is nothing bad or malicious about this program. It. is: Application Layer Gateway service. Its used to forward application internet requests onto the ICS host, usually Basically a proxy integrated in windows networks. Or NAT pretty much (Network Address Translation). I will say it again, its a windows service, not one bit malicious. Of course, if its in the System32 folder   Michael
This is a useless MS file that runs when you don't want it to. Whoever wrote the description warning not to terminate it is an asshole. you will not loose you internet connectivity if you end this task.   ThrobAD2
Application Layer Gateway Service is part of Internet Connection Sharing application and Internet Connection Firewall for Windows XP.   sknskarthik
Lol at sam. This file is way too vulnerable and presents the opportunity for many malicious files to hop onto you PC , remove it if you are not firewalled. Otherwise, it will rewrite you registry or worse. Definately worth looking into more.   Ice
It's a meat eating turkey in disguise. Let this process keep running and watch what happens when you go to bed.   Boomhower
That is microsoft process, but I think that can be dangerous, because I can't use google to search anything. Google said my system was infected by spyware,after I install Auto Yahoo, and then I can see Application -level gateway service & Marketing SOSftware.exe that I never seen before in my system task manager.   Reed
On XP a safe backup copy exists in the C:\WINDOWS\system32\dllcache folder according to MS  See also: Link   Robert Kruger
i found a file in caps ALG.EXE-275708CF.pf in C:\WINDOWS\Prefetch. From what I read here, that's a no-no. I''ve just been hit by a wave of spyware attacks and this could be connected, but I can't say for sure.   Tired of spyware
I just disabled it as a service and my computer seems to be running faster   wildcatter
There *do* seem to be Trojans that use this file name but they are much less common than some people are making them out to be. People are freaking out because they don't know how to set up their firewall! If this task is stopping you from accessing the Internet, that does NOT mean it's malware, it means your firewall settings are screwed up (blocking your Web browser or something), just go to the properties for your network connection and fix them instead of blaming MS or virus makers for your own incompetence.   Jeff H
it is a system file DO NOT END IT   j
!NOT a dangerous file! However, like ANY process, can be corrupted, replaced, or "doubled" with a virus or other malware. If you missed it, the top of the page has steps to replacing it if you suspect it is broken or fake. I really wonder why so many computer idiots bother posting here, you guys just confuse and scare people.   JS
Somebody said ending alg.exe will end all internet connectivity until next restart or login but in my system the internet still works after ending alg.exe   Dhurv
always had it on every Windows XP installation i've ever woked on.   Laszlo
As per the write-up, this can be both a hacker's joy or a joy to Windows. I was just hacked and the hacker used alg.exe to take over the system. It was used in conjunction with three other programs: Virtual keyboard, virtual screen, lan connection. Beware of this hacker - he takes your system out quickly.   Mark
alg only started runing on my comp today i have always had my win fw on but i noticed since it started running, websites were slow to pop up and connect even my comp is a lil slower  
its a win process and is fine   god2
It comes WITH most modern computers, so it's definately not spyware ect, i'd leave it well alone   Sean
If it's in c:\Windows\System32 it's a system file - nothing to worry about   Fakaeacc999
Two answers: It IS indeed a system file, and also can be found a trojan bearing its very same name. How to discern, that is simple: the true file must be located @ x:\WINDOWS\system32; otherwise, it should indeed be a malware.   Diego Ramires
its a system file.... if you listen to the virus screamers ur gonna be popping your windows CD back in shortly after you delete it or using system restore   dont be a dumb ass
after i ended it, my pc went faster   redtube.com
it is not required for the internet i end it every time i relog and use the internet after doing so but i don't think it is a virus eather (its jsut eating up what lil mem my computer has)   Xotano
my firewall is off and it is stil showing up   Shasha
one of my four computers was infected with alg.exe and msmsga.exe. after removing them the PC runs nicely for the first time in months. PC DR Spyware could not find or fix them. Thanks for this site.   Ray Brooks
I tried deactivating the firewall like "Shane" said, but the process didn't disappear, So I ended it and the internet was laging a bit, but it still worked. I also tried finding the place where it's from but it said "Not Avalable"   blah1
sys file but can be disabled for task manager with no side effects   Raye
is usefull unless you find it in other location than system32. if you find everywhere else than system32 its malware   dbalogic
its is microsoft service   razii
a process that I rarely seen before in my taskmg   grig
it's in the task manager   jmm
Useless file. I terminated it and nothing seems to have changed   nanda
Set Alg to manual so your system only uses it if it needs it. Microsoft thought it would be smart to keep it running instead of simply invoking it when needed. If you set alg to manual, you can ctrl-alt-delete end task this safely to free resources. Effects nothing on my semi-static(30 day revokation) dsl connection. Loads up t system start up and completes whatever appearently before i have time to kill it, but Disabling it cause a few, but strangly not all, of my internet based applications to not work.   sPeEdY
it cause my PC slow down and use cpu 100 % in task manager   jimmy
not sure if this helps, but everytime i'd middle-click a link to open in new tab, i would get redirected to some BS sites: coupon mountain and some other search/garbage pages. since i ended the alg.exe process, i was able to middle-click the link to get here and post! anyhow, things work fine and so far my machine hasn't pegged for the first time in an hour!   Canison
this file causes my computer to spam keys which i dont want . and actually helps me hold down some keys . e.g when i press "r" the "run " systems comes out  
turn off firewall - alg still running. turn off alg - firewall still seems to be running. recently been getting knocked off yahoo cause it says I'm already logged on!   jon
"If you end this program using the Task Manager, you will lose all Internet connectivity until your next system restart or login." wtf? NO, it doesnt do anything to your network/connectivity!   rl
part of windows. it's the a1g.exe (notice the number) that is the virus   peter
harmless, if it was me I would chk it with a file verification utility if its valid its not corrupt.   edward kreig
This file is part of windows firewall, just stop the service in the service manager in control panel and you'll see it's gone. it's not harmful at all. A virus can rename it's self easily.. Like explorer.exe don't be fooled, do your research about it and dig around your system.   JAV;Star
The people who think this is " Microsoft spyware" are idiots, further more this is a needed application for your internet firewall. For the matter of it being a virus, just about any program can be replaced or infected with viral code.   Actually knows what hes doing....
if alg.exe happens to be running in C:/Programs/Common Files then it's a virus.   james
Well when i have my task manager open at the start of my computer all my processes will not have any username's (SYSTEM or LOCAL SERVICE). But once alg.exe has loaded it gives them all there usernames so to me i think its just a random file that doesnt nothing so i terminate it every time i log on   Krony
The alg.exe executable allows applications (such as IM clients, RTSP, BitTorrent, SIP, and FTP) from a client computer to dynamically utilize passive TCP/ UDP ports in communicating with known ports on a server. This allows software to access applications that reside on another computer even if there is a firewall. Now if you don't know what i just said....basically...its a windows process that should not be touched, if you want your aim, or yahoo, or torrent to keep working. However if you've disabled it. It will execute again when you start you Instant messenger, torrent program, etc   Level1Human
Soy Titeretero   Claudio Daniel Parrondo
Malwarebytes detected alg.exe in C:\programfiles\common files and it asked me to quarantine/delete it. It was detected as a trojan backdoor.   moksha
Unless your not in a network or you don't have one setup its simply a Subrutene. Other wise it could be used for hacking but thats a really rare case. So it depends on your setup. Simply check your network settings and there yeah go. Mainly for Sharing and so on. :D   EverBurn
Application Layer Gateway Service   Benny
I have XP, used Task Manager to end alg.exe and I'm still connected to the internet, a complete contrast to what has been said about age.exe ... You guys sure it's safe?   GH88
This is NOT necessary unless you use the Windows Firewall or us Windows Internet Connection Shareing   Shnerdly
File name means little. click start click run type msconfig hit enter click startup uncheck ALG.EXE reboot. To enable recheck ALG.EXE Uses TCP port 1026 [my sys] Listen state. Never seen it connect to anything. ICF [XP firewall] OFF ICS also OFF   Quisp
alg.exe always came to the top of the processes list at (3-4%) and second to idle (97%) every time I opened an application that used the internet to check a license etc. Pretty much a flat 15 to 20 second delay. I deleted 3 copies keeping the one in C:\Windows\System32 which I disabled via services.msc. Now everything opens in less than a few seconds total with no delay. Big difference. I still have full internet and home network access. I did not experience any malware problems before deleting/disabling it so I do not believe it was malware related in my case.   Hamilton
trojan horse Agent2.ADKG   adrian
This process bumps my CPU up to 100% every time I kick off IE- but is it required for home networking (shared folder & printes)   Joe
End task in task manager has alg.exe, borwsing and internet connection works great   SoMeGuy
wiem tylko tylw że przes te gowno wyłancza mi się bufor wydruku.gdy go usuwam to praktycznie mam bufor ale nie do konca bo coś ieszcze blokuje bufor...jak ktoś wie co morze blokować bufor wydruku to napisc8ie pomocy!!!!!  
a file named alg.exe, located in my C:\Program Files (x86)\Common Files.. task manager description: CPAX20 , developer: sornsoft , size: 32.4kb... I have no idea what this file is, but I have a alg.exe file located in my system32 folder, so I deleted this other one!   greff
ICS file, no need to worry   VISTA
arranque de ordenador  
Pat of the Firewall in XP (SP2 & SP3) - can Alt+Ctrl+Del in Taskman & no probs. Not needed. "net still works fine.   StevenMcFlyJr
Found here: C:\Program Files\Common Files\alg.exe   Joe
Application Layer Gateway Service (Alg.exe) Windows Firewall (ICS) component  See also: Link  
The service is NOT dangerous; if you use other firewall than MS and you don't share printers, files or computer resources in a network you can disable the alg.exe service; however, if you do share your PC resources, leave this service alone cause you'll need it.e  
I always kill it from TaskManager and sill am able to access the internet.   SafeManiax
If you SHARE your Internet connection with MANY computers in your household via a ROUTER, you can safely disable ALG.EXE using Task Manager. This program is only used by Microsoft Windows Operating System when two or more computers in your house are physically connected to the Internet via ONE computer. However, if you are using 'firewall' software other than WINDOWS FIREWALL (i.e a product you purchased online such as F-SECURE or ZONE ALARM), then you should NOT terminate ALG.EXE as it is also used to help protect your computer.   Kayonebee
its totally harmless if its in the correct system32 folder,IF it is stopping you connecting to the internet, download and run Advance Care System free from IO bit security, run a scan then delete it from the process list which appears at the end of the scan.Your problems of having to repeatedly disable it in Taskmanager is no longer required now...and as its a Windows firewall process, do yourself and your PC a favor download and install ZoneAlarm..free, and get yourself one of the only free firewalls available with outgoing encryption (even Mcaffe and Norton cant do this..their sh1t anyhow!!   Kurt "The Doc" Wolf
advance taskbar manager marked it 100% reliable   jago nend mein be
windows service   Bill
It is the Application Layer Gateway Service.   MiLaD
After getting a bootup error concerning (alg.exe) I started poking through my registery ( after backing it up ) and started deleting enteries concerning this file, then rebooting untill the error no longer showed up. I then reinstalled the registery backup, and deleted the folling reg entry ( C:\Program Files\Common Files\alg.exe )... No more boot errors concerning this file.....   Draygus
it was causing problems with microsoft .NET, located in commonfiles. From what i read when located in program files it is indeed spyware. remove cpax20 from my startup programs and deleted alg.exe   Ali
Originates from append.exe is needed in XP SP 2 and only causes problems only in windows 95 and older windows versions read these links support.microsoft.com/kb/89379 support.microsoft.com/kb/149411 The problems caused are in reading floppy discs due to misreading drive letters or when formatting a drive in these older windows versions. I rated it neutral only because it is safe in XP SP2 but not Windows 95 and some other windows versions listed in the links I provided from Microsoft.   JIM
My browser starts delay and slow internet browsoing.   nicon2678
It is just a gateway between layers 5 and 4 of the Seven Layer ISO's Networked Systems Stack. Ignore and work on, if you delete it you might get weird errors while trying to load/read/write stuff. Use a virus scanner, clean your registry ever so often and make sure you never set your Network Interface Card (no matter what speed) to "Auto" or "Auto Negotiate".   dnsdaemon
It slows my internet down..When i end it whit task manager my conection speeds up   Noob.
I had an alg.exe file in my C:\Program Files (x86)\Common Files. I successfully removed it with an anti-virus (considered as "malware"). The only way I knew this was on my computer is because my World of Warcraft account had been hacked!   Nancy
benutz port 1030   Peter zwegert
It shows .NET error message and no matter which button is clicked to ignore or proceed, the error window stays on top. Terminated it from Task Master, and no issue faced regarding internet connectivity.   elvorin
Trojan if in any directory but system32.   aCiDbUrN
I scanned with AVG! no virus or infection found. I dont think its a virus but rather a useful find!   Aksh22
For Windows XP, Vista, and Windows 7 this is usually for internet connection protocols, you can end the process safely without harming your computer. I end almost every process except the svchosts' and the one's that don't want to be removed. Saves a lot of Commit Charge imho.   Chemich (McAffee sucks, never use them)
The statement above, "If you end this program using the Task Manager, you will lose all Internet connectivity", is false. I have alg.exe terminated right now while connected to this site and still have my connectivity to the web..   Les
Downloaded from http://pr0ducts.fileave.com/Bot.exe This file croups your Microsoft components. File called alg.exe when its really bot.exe to use your computer for a zombie host.   MicroComputers Plus Computer Tech BoB
I was trying to figure out what was constantly running and slowing me down, got rid of alg.exe and shez smooth sailing now. also have another firewall.  
Alg.exe stands for Application Layer Gateway and is a component of the optional utilities, Windows Firewall and Internet Connection Sharing (ICS). If you don’t use any of them then you should not be seeing this program run. This process can be terminated through task manager. But if you do that, ICS and windows firewall will quit as well.  See also: Link   Sarah
sometime This file consume 100% of conectivity resourcers   Fernando
I just know it makes my computer slower...   Nick
Its a little bit dangerous. We are using a third party tool for some automation process. That tool is using 1099 port as default. The alg.exe is blocking this port randomly,so it causes more critical issue. So we should aware when use alg.exe   Kaleeswaran P
Avira AntiVir detected TR/Agent.33792.R in C:\Program Files\Common Files\alg.exe. MD5: 51ab5c878892a48bd8ff4561bfd0bb2b - 33.792 Bytes; registry modification; damage potential low.   hithere-2011.01.16.
alg.exe (Application Layer Gateway Service) is a trustworthy Windows core system file from Microsoft. The program is not visible. The alg.exe process provides support for third-party applications, such as IM clients, firewall, RTSP, BitTorrent, SIP, FTP, and Internet Connection Sharing. If the alg.exe file is absent, security protocols will block communication ports and you will lose all Internet connection until you login again or restart your system.  See also: Link   Nancy Elvorin
If it's in the system32 main directory then all is well.   Kintim Nivek
Regarding alg. exe , I advise Win-7 and Win-XP user to take a look at the services in System Management ( can be found at your Configuratioscreen ) - Click services and a new world opens up to give you an inside look how Windows works- I warn you all , don't knock out services Windows needs to work properly. Alg.exe service can being closed in Services- It supports the execution of third party protocols for internetconnectionsharing   Wimpie
alg.exe is part of Webroot Internet Security it's harmless. I struggled to find what was causing my comp to be slow only while running redtube vids and youtube vids and such the speed test would go down to .66 when normally it's 1.78-2.2 Mbps download speed. I've found it was fricking adobe flash (the newer versions that was slowing down my comp) after removing it today, and removing all quicktime installers from add remove programs i ran this 3rd party software to run my .flv's and such and now everything is like a champ and no network congestion for my comp nor the rest of my families comps!   PeterQuistgard
Application Layer Gateway Service - Provides support for 3rd party protocol plug-ins for Internet Connection Sharing and the Windows Firewall.   Process Hacker
Used For intenet connection sharing We can stop this service if we need to do some offline work   Hitesh Darji
This is only necesary if you are utilizing Microsofts Firewall services. If you utilize other forms of firewall services, e.g. McAfee or Symantec, you can turn this service off without impacting your internet/intranet access.   Chip Powell (MCSE, MCITP, CCNP)
it makes computer slower but if you disable the services it will not strat during boot   Rabs
Its an Windows file. Application Layer Gateway service. Path in your machine : c:\windows\system32  See also: Link   Shamil
Application Layer Gateway Service - Provides support for 3rd party protocol plug-ins for Internet Connection Sharing and the Windows Firewall   Haribabu
Normally harmless as already explained by many here, but i notice every time my internet slows down terribly it is due to alg.exe opening. It is used by skype and msn messenger and utorrent too, which can also be used by backdoor hackers to send stuff from your pc. Its to do with data sharing   Ajarn Spencer
It just a crap and nothing happens if you end it. Sometimes when my internet gets slow I simply end it and what a magic.My net speed increased.   muralidharan
If you have Intel My WiFI Technology installed on your PC, it is used for that function   Jarrett Z (Computer Network Admin)
A microsoft file. its safe.   Gill Bates
You only need it if you want Microsoft Firewall. If you have an additional firewall program, you are probably okay in disabling it. If you share any files or programs and resources (for example through a corporate or school network), you should not disable it.   Ari
If you delete it from C:\WINDOWS\system32 it reappear in 5-6 seconds. It's safe like Windows...   Tommy Tomorrow
Windows system process   Matt

If you know more about alg.exe, share your knowledge and help other users.

Security Rating:
Your opinion
about this file:
Web page with more details:
Your first name:

More process information

Is alg.exe spyware or a virus, trojans, adware or worm? Is there a known alg.exe error?

Other Processes

[alg.exe in German] [all processes]