I think it might be the K-lite codec, I've used it myself and had similar problems - none so extreme fortunately.
As has been previously said, re-install your drivers. Completely remove them from the Device Manager panel and download them from the nVidia site - preferrably in safe mode.
I'm 95% positive you want these:
http://www.nvidia.com/object/winvista_x86_175.16_whql.htmlThey were released last week, 37mb file size and in US English for Vista 32bit. Supports all 8800 models, incl yours.
P.S.
I know this is an old topic but
1) I'm looking for posts xD
2) Trying to help others with the same problem
3) Wanna know how it went on