My computer is running Windows 10. I have kept Windows defender on as it was light weight and just worked in past versions of Windows.

However, in Windows 10.. I find that for about 5-10 minutes of resuming from hibernate, multiple msmpeng.exe processes cause disk usage to spike to about 100%. Obviously, its running a scan.

How can I stop the Windows defender process from running immediately after powering on my computer? Can I keep real time scanning on and still delay the rage inducing behaviour caused by Windows Defender?

  • 2
    Do you have Steam installed on your computer?
    – EntMobSec
    Sep 23, 2015 at 15:58
  • This may be normal if the scheduled scan task has been missed, check Control Panel>Admin Tools>Task Scheduler>Windows>Windows Defender, check the "Windows Defender Scheduled Scan" task settings, they may not be set for your needs.
    – Moab
    Sep 23, 2015 at 21:47
  • @OfflineFiles: What has Steam have to do with it? (And how to fix it, it does??) Aug 29, 2016 at 20:09
  • It was a common issue at the time I wrote that
    – EntMobSec
    Sep 6, 2016 at 11:53

2 Answers 2


To disable this behavior, try these. For some genius idea, that file is scanning itself. I am sorry but I really can't explain why is that happening. Adding it to the exclusion list, fixed for mines and for my friends. That's how I came to that conclusion. I have also experienced similar situation and this worked.

Anyway, let's fix it!

Open Task Manager, and right click the "Antimalware Service Executable" and choose open file location.

Once you opened file location, you must the copy the directory from the address bar.

Now, go to Windows Defender , go to Settings > Excluded files and locations.

In first box, paste the path and click Add The path will show up on the second box Save changes and your problem must be fixed. Please note that this procedure is a workaround, it reduces the protection, it excludes scanning the mentioned path. If that's not a problem, go ahead and give it a try.


  • How do you know its scanning itself?
    – Moab
    Sep 23, 2015 at 21:52
  • @Moab, adding the exclusion fixed for mines and for my friends. That's how I came to that conclusion.
    – 1NF1N17Y
    Sep 24, 2015 at 10:01
  • Ah, add this info to your answer please.
    – Moab
    Sep 24, 2015 at 11:46
  • Should this bug be reported to Microsoft?
    – user446730
    Dec 29, 2016 at 19:20

I went into widows defender settings and excluded C Drive. My copy / paste operation went from around 8.5 minutes for 121 Mb to 1.25 minutes Copy operations were in the 1.5 - 4Mbps range, not the 100kbps range.

There is an app to disable Windows defender on windows 10, here. I have no experience of this app.


  • 2
    This solution seems extremely unsafe as most viruses will install on your C: drive. Excluding your drive from Windows Defender would allow lots of security issues unless you run another antivirus software
    – Aserre
    Sep 27, 2016 at 9:53

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