i maybe very wrong but this worked for me. Double check your bios settings for your card. I have nvidia vanta and when things were getting intense like crashing everything would freeze. on my card for bios settings everything having to do with video shadowing has to be disabled. My vid card is agp so i had to make sure the agp sizing in bios settup was set to the mgb size of my card which is 16. If you are attempting to overclock your cpu, core mem on vid card, mem on vid card or casche that maybe a problem too. I dont know your specs but it worked for me.
Cya up there