i actually had the same problem too...i did 2 things:
1.i formatted my pc and re-installed a new windows...had a lot of problems with other games and when i shut down my pc, i always had an explorer.exe problem...it still didn't work though the game still freezed but i could play longer,for like 1-2 hours
2. i bought a new graphic card(instead of another nvidia i bought an ati,'cuz people say that it is best for gaming...),installed latest drivers and...it worked, i managed to play for like 5 hours non-stop and no crash...
so my best bet is to find a better graphic card or else do not overclock your system and stuff
Well that's just a big load of guessing there mate ^^
There IS no such thing as a superior GPU maker as of today. (There WAS though, back in the age of Voodoo ^^ ahh, the memories...)
And for the record, nVidia now has real high-end cards, while ATi/AMD has their highest-performance cards in the mid-segment.
Would be nice to see some new ATi/AMD real high-perf. cards though
One thing I can agree on with though, is the fact that you shouldn't overclock, since the performance gain is not worth it compared to the VERY (Yes, very! It's more "dangerous" than most people think) decreased lifespan you get out of your CPU/GPU/Memories (RAM, GRAM etc. depending on what you clock).
Ah, anyway, the thing that the OP describes can be a lot, if you don't have the patch installed, install it. And if you have it installed, re-install the game and try to run without the patch.
This is actually really possible to help, as several people experienced this before the new patch, and several others experienced it after.
Oh, and try with another set of drivers (newer if possible).
Don't worry, as long as your card meets the requirements (plus some more, just to be on the safe side) you don't need to re-install Windows or buy a new Graphics Card.
That's the solution when all else fails, or if you have extreme problems with your current installation of Windows or your Graphics Card.
Cheers!
/Chris
[Edited by PeTTs0n, 7/27/2007 4:15:43 AM]