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I've been using MSE for a couple months now, never had a single problem. All of a sudden the process "MsMpEng.exe" will randomly go crazy and hog all my system resources so I can't do anything unless I kill it in the task manager. (I've quit the program for now and my comp is running smooth). When I restart the program, reboot, whatever, it goes off and hogs all the resources again after a couple minutes. If I kill the process it will go away and then come back a couple minutes later and do the same thing. I've scanned with MSE, another antivirus and malware with no probs. Any ideas? Should I uninstall and find something else? The thing is I've liked it so far. I'm running Win7 64-bit.

Also, I'm not running any other conflicting security programs. This is the only one on my PC right now. Windows Defender is also off.

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What resources are you talking about? CPU/Memory/IO/...? – Tom Wijsman Feb 12 '11 at 23:34

You can adjust the amount of resources MSE uses. The following settings can decrease the resources usage without greatly effecting the effectiveness of MSE.

  • look at the settings tab>"scheduled scan" settings in MSE you should see the option to limit the cpu usage from 10-100%.
  • look at the "real time protection" settings and see what effect unchecking "enable network inspection system" and "enable behavior monitoring"
  • look in the "advanced" settings and see if "scan archive files" or "scan removable drives" are enabled.
  • verify your install is fully updated
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+1 Didn't know that MSE allows you to limit CPU usage, nice! – Tom Wijsman Feb 12 '11 at 23:33
Pretty sure the culprit was the behavior monitoring option. As soon as I disabled it and saved settings, CPU usage dropped considerably. – Christopher Parker Jul 14 '11 at 14:43

Not the ideal solution, but you can attempt to set the process affinity to a single processor core so it can't take all the resources. This should leave your other processor core to do the other tasks you need.

This only works if you have a Multi-Core CPU obviously. :)

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This hogs a complete core, and will bother programs that use multiple cores. It might be more than just CPU. – Tom Wijsman Feb 12 '11 at 23:34

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