NVIDIA has released ForceWare 174.53 official WHQL certified drivers for Windows Vista.
-Added support for GeForce 9800 GX2, including Quad SLI Technology.
-Added new PureVideo HD features for GeForce 9800 GX2:
-Dynamic Contrast Enhancement
-Dynamic Blue, Green & Skin Tone Enhancements
-Dual-Stream Decode Acceleration*
-Microsoft Vista Aero display mode compatibility for Blu-ray & HD DVD playback*
*Note: Users will require updated software from third-party movie players to experience the new Dual-Stream decode acceleration and Aero support for Blu-ray and HD DVD playback features.
Release notes (.pdf format)
Vista 32-bit | Vista 64-bit