i had exactly the problems at 8% as you have. i simply put windows 7, i was so fed up and out of clues after done every system update, i suppose it was some weird compatibility issue and it was, well maybe updating to 195 will help!
i have tried the latest Nvidia BETAs and tht has not helped. I have tried changing sound drivers, reducing sound acceleration, defragging, re installing the game, and trying it without the 1.1 patch.
I'm so frustrated because its such a good game but pretty much unplayable - although I have somehow manged to get to about 25% way through but thats spoling it really because Ive been playing it in slow motion and with stuttering sound!!
Weird how the game was totally playable and smooth until about 8% way through. I kept getting BSOD at the same place in the game at that point and then after I installed the 1.1 patch and the latest Nvidias to fix the BSOD it all went crazy wrong.
Actually the slow down in this game is very much the same as the one I had trying to play GTA4. COuld be some sort of memory leak issue?
Holy Cow! I just opened up my PC and it is totally caked in dust. The CPU heatsink is almost totally blocked. I think my probs could well be caused by overheating. Gonna but some compressed air in the morning and give it a good clean up see if that helps
OMG this is embarrasing to admit but i hope it helps anyone else!! I cleaned most of the dust off my cpu just by blowing and using cotton buds and fired up the game - its now running smooth as a babys bottom!!!