Problems with Nvidia display driver 185

I recently installed a gtx 285 graphics card (the 1 gig one) it ran fine for about a day and since then everytime it runs for more than a few minutes I get popups notifying me that my display drivers stopped responding. this repats a few times and eventually the screen either goes completly black or pixelates randomly. after a few minutes it usually BSOD's and thats that.

I'm about to do a full reinstall and hope this solves the problem.

is this likely to be a hardware probem or a software problem.

System specs.

S-series gigabyte p965 mobo
4 gigs ram
and a piss poor core 2 duo 6300

incidently its dual boot and this problem seems to exist on XP aswell. to a lesser extent..(alot of games crashing etc...)