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.
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.