I have recently upgraded my laptop from Windows 7 to Windows 8, and now 8.1. After the upgrade I observed a very high disk usage periodically (almost every day), caused by some weird TMP0000000XXXXXXXXX... (TMP000000000 followed by a bunch of string, one example is: TMP00000003673F37CC1586E0CB) files without extension in %WinDir%\Temp folder as seen from Resource Monitor, and there are about 10 of them.

I did some investigations and eventually found out that Windows Defender is actually the cause of this problem. I'm very sure about this. WD just anyhow uses up my harddisk resource even when there is no scanning activity. My laptop becomes incredibly slow, and I know it would decrease the lifespan of my HDD. When I disable it, all those weird files suddenly disappeared, and the disk usage just comes down to around 0-5% (normal percentage).

Is there any way I can stop Windows Defender from slowing down my laptop without changing the antivirus software? I know Windows Defender isn't bad, and I want to keep using it. Thanks.

PS. Actually I wanted to show you guys a picture of what the files look like, in case you don't get it, but my reputation is not enough.

  • Do you have any other antivirus on your system? – Matthew Williams Feb 10 '14 at 12:57
  • No. Only Windows Defender. – brillydev Feb 10 '14 at 12:58
  • Have you checked to see if it is running a scan every time you boot up? Check to see if it is running a full system scan. – Matthew Williams Feb 10 '14 at 13:01

Following a look around it seems you are likely suffering from a couple problems. Either Defender is caught in a loop, which will keep it running a scan constantly taking up resources on your system. If you wish you can run this offline by creating a live CD/USB. You can find a copy of Windows Defender Offline from Microsoft

The other option to this would be reset it to default, but according to a Microsoft answer here, you would require a registry edit to do this. I suggest you try a complete removal of your antivirus and run a clean install. This should solve either of the above problems. If not it might be a system problem which we can asses.

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    sfc/ scannow itself solved my issue, it showed some resource correption and was repaired – Arun Prasad E S Jul 29 '16 at 16:43

Windows key + X and select Command Prompt (Admin) and type sfc /scannow and return. If it repairs system files, run it again until no errors.

In case Windows Defender is caught in a loop, consider running it offline per the following tutorial..


If this does not solve your problem, restore the default settings of Windows Defender Services only per the following tutorial


If the problem still persists, you may have to Refresh Win 8.

scanning itselft solved my issue

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I found that doing a definition update from windows defencer fixed the issue, as per this post on itsupportforum.net

If it fails. simply try again.

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I was also experiencing this issue and found the cause to be something totally unexpected. Although my iObit Advanced System Care was showed only 1-3% usage when no programs were open, Windows Task Manager showed 100%, and my computer was operating very slowly. This was after a definition update, so YES that was a factor, but the Windows Defender reported the update as successful, yet Task Manager still reported 100% usage even when Windows Defender wasn't actively scanning. When contemplating what might be causing the disparity, I remembered that I'd disconnected two external hard drives the previous day to troubleshoot another issue, and hadn't reconnected them. As soon as I re-connected the external drives, the disc usage dropped back down to normal. I can only surmise that Windows Defender was spinning its wheels trying to scan the discs it was accustomed to finding online.

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