This is the beta driver for XP that is supposed to clear up issues the 8800 series has with the la-*test*-('") games. http://www.nvidia.com/object/winxp_2k_163.44.html

There is also a new one for Vista users readily available under Beta drivers at the Nvidia site.

Actually, the new Vista drivers from Nvidia are now official and not beta as of today.

Vista 32
http://www.nvidia.com/object/winvista_x86_163.69.html

Vista 64
http://www.nvidia.com/object/winvista_x64_163.69.html