Windows Defender keeps terminating

Today Windows Defender was scheduled to do a full scan, but when I went to check it, it was off, the last full scan being two weeks ago (it's been updating two to three times a day on a separate task). Trying to start it, I got the error that shows in the screenshot. Then I enabled the service and a full scan, only to come back later to find it terminated (in less than two minutes). Repeated just to be sure. Events Viewer showed the errors below. Is there any way to fix this short of refreshing or reinstalling Win 8? After a couple of dozen hours installing Win 8 and setting up two accounts in a dual boot system, that's not something I'm inclined to do again for an app that's readily replaceable. A System Restore seems out of the question, since Windows Backup runs every day and this has to be at least 8 days old. Thanks,

Event ID 7034: The Windows Defender Service service terminated unexpectedly. It has done this 3 time(s).

Event ID 1000 Application Error:

Faulting application name: MsMpEng.exe, version: 4.0.9200.16384, time stamp: 0x5010a938
Faulting module name: mpclient.dll, version: 4.0.9200.16384, time stamp: 0x50109ed2
Exception code: 0xc0000005
Fault offset: 0x0000000000006bc5
Faulting process id: 0xaec
Faulting application start time: 0x01cddfc5e14c7ee1
Faulting application path: C:\Program Files\Windows Defender\MsMpEng.exe
Faulting module path: C:\Program Files\Windows Defender\mpclient.dll
Report Id: 8598f9a1-4bba-11e2-bed4-50e549cfa7ae
Faulting package full name:
Faulting package-relative application ID:

Hello there,

A quick search on Microsoft's forums indicates that the problem may be caused by other antivirus programs, hardware issues, or possibly malware. If you are running any other antivirus programs, try disabling or even uninstalling them, then try again.

If the problem persists, and you have not recently changed your hardware setup, try booting into safe mode. If all else fails, I may recommend using the System File Checker.

Press WinKey + X, then from the menu that pops up, select "Command Prompt (Admin)". Then, type "sfc /scannow". This command may take as long as several hours to complete, and will reset all Windows files back to their defaults. This command will not touch your personal documents, applications, etc. You may be asked to insert your installation media at some point during the process though. If errors occur during this process, I think your only hope is to reinstall/refresh/reset.

Or it may not be. While I thank you for looking it up, I have to admit having expected someone would come in with this (which I've already seen). Claiming conflict has *always* been the pat answer on Microsoft's forums, and it's *never* their own product that they suggest uninstalling. That doesn't mean in this case (Win 8) MS hasn't intentionally used its monopoly position, although if they had one would think other companies in the antivirus/spyware sector would have said something, if not be screaming bloody murder. Have you heard of any? Under XP and maybe Win 7, there are/were some other antimalware products that don't share the stage well, but in my years of experience SAS Pro has not been one of them.

It's been about eight hours and Defender is still running alongside the reinstalled and active SAS Pro.

highstream said:

Or it may not be. While I thank you for looking it up, I have to admit having expected someone would come in with this (which I've already seen). Claiming conflict has *always* been the pat answer on Microsoft's forums, and it's *never* their own product that they suggest uninstalling. That doesn't mean in this case (Win 8) MS hasn't intentionally used its monopoly position, although if they had one would think other companies in the antivirus/spyware sector would have said something, if not be screaming bloody murder. Have you heard of any? Under XP and maybe Win 7, there are/were some other antimalware products that don't share the stage well, but in my years of experience SAS Pro has not been one of them.

It's been about eight hours and Defender is still running alongside the reinstalled and active SAS Pro.

Click to expand...

I get what you mean. Microsoft has ran into antitrust issues in the past before, and they always say "Its somebody else's problem." Often times, the third party software even works better than theirs, but they refuse to let you uninstall their side of the conflict. I don't think that I've heard any antivirus companies complaining though, but maybe it has something to do with the fact that it's MS's operating system and MS could possibly bar them out if they did (not sure here, but just look at Mozilla when they tried to make a Firefox metro app).

My Defender works okay alongside Avast, Malwarebytes', and Spybot S&D, but Avast has been experiencing errors since I upgraded.

Right now, I working on the possibility that it's Comodo Firewall's Defense+. I noticed in the Action Center a message under "Spyware and Unwanted software protection" that running both can slow the computer. Nothing about conflict. Just experimenting, I Disabled Defense+ and immediately Win Defender came back on. And it's stayed on thus far (nearly 40 mins)...except for three moments exactly 11 minutes apart to the half second, and then again a few minutes after the third (but nothing this time in Admin Events). At that latter point, I was able to restart it directly, unlike what happened before disabling Defense+, when it required restarting the service. Have to see what happens over the course of the day.

To pick up again, I uninstalled SAS Pro and Comodo free Firewall - RevoUninstaller Pro, Ccleaner, jv16 PowerTools and finally deleting from the registry all instances "Comodo," "cfw" and "SASAnti." Alas, Defender Service still cuts out and Defender's dialogue box turns from green to red after 5-20 minutes, with a couple feints in that direction along the way. At MS Answers forums, the help, an MVP, really didn't seem too keen on this type of matter. So I'm back to see if by chance anyone here has an idea what might be causing this short of a dreaded (and probably not going to happen) clean reinstall of Win 8. Thanks,

When the Service cuts out, whether momentarily or completely, there are two Adminstrative Event errors:

Event 1000 - Application Error:
Faulting application name: MsMpEng.exe, version: 4.0.9200.16384, time stamp: 0x5010a938
Faulting module name: mpclient.dll, version: 4.0.9200.16384, time stamp: 0x50109ed2
Exception code: 0xc0000005
Fault offset: 0x0000000000006bc5
Faulting process id: 0x139c
Faulting application start time: 0x01cde7c599dbf62e
Faulting application path: C:\Program Files\Windows Defender\MsMpEng.exe
Faulting module path: C:\Program Files\Windows Defender\mpclient.dll
Report Id: 3d83c152-53ba-11e2-bf01-50e549cfa7ae
Faulting package full name:
Faulting package-relative application ID:

Event 7034 - Service Control Manager:
The Windows Defender Service service terminated unexpectedly. It has done this 3 time(s).

A quick google search for the components referenced shows dire results saying "uninstall/reinstall MSE", which is unapplicable in this case. Therefore, your fastest and probably easiest plan of action is to run the SFC scan, and if that fails for whatever reason, try a refresh/reset.