The latest drivers for XP and Vista are out from Nvidia. They are a big improvement for sure. They include the latest PhysX engine drivers etc.
One of the biggst improvements are: GPU increases on avg. up 11% +.
I first installed on Vista and played some 'Crysis', and tehy are simply great. graphics looked much better,and most any previous artifacting ( you kknow the glimmmer in frames out of sync ) went away and the FPS was alot better. I am playing it on DX10 with no lag at all. LOL
If for whatever reason Nvidia is slow on this, i suggest going to Guru3D.com. Thye have all the latest and beta drivers of course.