This error reportedly sometimes is caused by a CPU heat issue.
If you're open to the idea, you may want to pop the side of your case off and verify that your CPU fan is running properly and not stopped up with dust. It is probably a good idea to rule out this possibility first to prevent permanent damage to your hardware. Please be careful not to touch anything without grounding yourself (grab onto some metal, such as the case exterior) or you can zap your motherboard dead with static electricity.
Apart from that, this can be caused by a range of different problems: badly seated memory (unlikely in your case unless you recently upgraded), incompatible CPU/motherboard combination (again, in your case, unless you've swapped/updated...), bad BIOS version (might want to try a BIOS update here), video card or driver problems...
For completeness' sake, you can also try this:
1. Click the Start Menu, and in the Start Search box, type %SystemRoot%\Minidump and press ENTER.
2. Zip and attach the last few .dmp files to your next post so that I can analyze them for you.
Also, as an aside, do you happen to be running beta drivers for your video card?
Edited by othersteve, 19 November 2009 - 11:58 AM.