Windows 7 laptop freezes after an hour

Question

I have a laptop with Windows 7 Enterprise. If I leave alone for an hour then the laptop freezes. I have checked all the power options so that nothing kicks in (like hibernate, etc.) after an hour. I finally just checked my event log after it happened again today, and there is only one entry, about an hour after I stopped using it:

The disk defragmenter successfully completed defragmentation on System Reserved

Could that be the culprit? If so, what should I do to fix it? If not, what else can I try?

Edit

In case this can help someone else, I was able to disable defragmenation on just the System Reserved disk. Now a defrag can still happen on my C: drive.

Answer 1

If you want to know if the defragmenter of Windows is the culprit you can disable it (temporarily).

1. Click Start.
2. Click Control Panel.
3. Click System and Security
4. Under the Administrative Tools section at the bottom, click Defragment your hard drive
5. Click Configure schedule
6. You may need to grant permission to open the Configure-dialog.
7. Un-check Run automatically (recommended)
8. Click OK

and see if it hapens again after an hour.