mousemonkey will probably post something telling you not to bump posts later xD
Anyway, are you up to date on Windows updates? Have you tried running memtest? If these things check out OK, I would probably suspect some problem with the motherboard or even maybe the PSU. I'm not too confident in Cooler Master's PSUs.
Edit: Forgot to ask, did you install any new programs before this started happening? Or was there a Windows update right before this started happening?