Well, the first thing I would try is updating all of your motherboard, video card, and sound card drivers.
Get
DocMemory from simmtester.com and test your RAM.
Also check out your hard drive with a diagnostics tool from the manufacturer (Western Digital's DataLifeguard, Maxtor's PowerMax, etc) to eliminate the hard drive itself as the problem.
Then check hardware settings for the hard drive in the Device Manager and the bios.