Nvidia has released new ForceWare drivers for Windows XP, Vista, and 7

This driver adds support for the new GeForce GTX 590 dual-GPU graphics card, including support for Quad SLI when paired with a second GeForce GTX 590 card.

For 3D Vision support, you will also need to install the NVIDIA 3D Vision Controller Driver v266.21.

Other

Installs HD Audio driver version 1.1.13.1
Installs PhysX System Software to version 9.10.0514
Users without US English operating systems can select their language and download the International driver here.

Download for Windows XP 32-bit
Download for Windows XP 64-bit
Download for Windows Vista/7 32-bit
Download for Windows Vista/7 64-bit