I'm using Windows 7 Ultimate. I get a problem with two processes: explorer.exe and sometimes dwm.exe.

The two processes tend to have a CPU usage between 20-30%. It only occurs when I play games on my PC - the PC works perfectly otherwise.

The processes consume no CPU as such, only really consuming CPU time when I try to refresh my desktop. When I right click on the desktop it takes a noticeable number of seconds to refresh.

I have no virus problems.

I've tried the following things:

  • Killed explorer.exe and relaunched from Task Manager: problem still persists
  • Killed dwm.exe, it relaunched again: problem still persists
  • Logged off and logged back on: problem still persists
  • Restarted the machine: problem solved, but need an alternative

Can anyone kindly suggest some quick fixes to this problem?


The explorer problem sounds like a misbehaving shell extension.
Shell extensions are Windows Explorer addons that add additional functionality. CD burners, compression utilities, some backup systems, and other programs will add shell extensions to integrate with Windows Explorer.

However, a poorly-written shell extension can slow down your machine. Since they are explorer addons, they would show up as CPU usage in Explorer.exe.

Use this utility to disable every non-Microsoft extension that you don't actually use.

You can also run Process Explorer and look at the call stacks of the misbehaving processes to get a general idea of what they're doing.

  • 2
    @Nitinzz: What was it? – SLaks Mar 8 '11 at 13:04
  • Well even after i play games, refresh doesn't become slow now. But recently It took some seconds for refresh after i play game and it continued until i restart my PC. – Nitinzz Mar 10 '11 at 13:00
  • 5
    If it was a shell extension, what was the name of it? Inquiring minds want to know. – TuxRug Apr 29 '11 at 19:12
  • 6
    @Nitinzz what shell extension was it? – Flak DiNenno Aug 28 '13 at 20:57

The DWM process is the 'Desktop Window Manager' process.

I would say that as you notice the problem when gaming then first thing to check is that you have the latest graphics drivers?

  • yes, i have updated all my drivers.Also I have windows update on in my PC. But still the problem is there. – Nitinzz Mar 7 '11 at 14:51
  • I had a problem with "dwn.exe" using CPU and slowing down the Windows UI to a crawl and causing stuttering/fps-drops all over the place. In my case it was because of Multiple Monitors + ShadowPlay in the latest nVidia drivers. I disabled ShadowPlay then ran a clean installation of the same driver I was on and it went away immediately. As long as I stay away from recording atm. this does not happen. – andersevenrud Nov 13 '14 at 23:04

Clear out as much from c:\windows\temp\ as you can, then kill and restart explorer.exe. (Source)

This made a big difference for me. I'm not quite sure what explorer would keep wanting to do with its Temp files - but whatever it was it was driving me crazy spinning up the fan all the time.

Using Process Manager you can view a graph of CPU usage per application. Even with no virus protection running - once I removed files from temp it hasn't been spinning up.

You can also show a mini CPU graph per process - just right click one of the column headers and select 'Choose columns'. I can't see a way to reset CPU time - but if you did this right after a reboot you'd get to see what was cumulatively using your CPU time.

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Start, right click Computer, and click Properties. Click Advanced System Settings and under the "Performance" option, click Settings. Select "Adjust for best performance" and click OK.

Or configure Custom visual effects - Try to turn of one-by-one.

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