Wow, that's rich. I have changed vid drivers several times using the latest VISTA 64 bit drivers and using the W-7 beta driver with no problems. When I change vid drivers, I uninstall my vid cards via Device Manager and reboot to Safe Mode. I install the driver in Safe Mode and reboot to w-7. I'm running a GTX 260 & a 8800GT for PhysX. The only twist I have ever had, was that the PhysX driver did not install initially. I installed the driver by locating the extracted driver under the NVIDIA folder. Other than that, I have found changing vid drivers in W-7 pretty smooth.