PC reboots randomly

[rohitk89]

I have the problem some too.

I ran CCleaner to clean the PC of unused files and issues with the registry. Then I ran RegCleaner to remove unwanted software/old software fiels and ran a full scan with AVG, Ad-Aware and Housecall. No virus/spyware was detected.

I should also add that the same thing happens with FireFox (I get the 'send error report' message 80% of the time) and that all this started when I got more RAM added (256MB->768MB)

The PC reboots about once a day on average and Firefox about twice.

edit: I'm not overclocking and Microsoft Update shows no available updates for my audio/video drivers. I'm running Windows XP Professional with SP2.