BSOD at Startup screen

[Grevion]

The game used to work perfectly, and then it just started crashing after an update (i'm not sure which)

So far, there's literally nothing i can do to get it to work. I've redownloaded the game (bought it on Steam), wiped my hard-drive and reinstalled my OS, deleted the Creative Assembly folder in Documents and Settings, borrowed a copy from my friend and installed it without updating, verified the integrity of the data cache on Steam... i'm stumped :/ it used to work perfectly, which is why it's so frustrating

I also get the same problem when trying to start the Napoleon: Total War demo. Any thoughts?

(Oh, and when the computer blue screens it crashes to fast to be able to read)