good idea to delete every single video driver you have on the system and install new ones, just incase they are corrupted, this program does both uninstall then reinstall over the top of the latest drivers. while i could delete drivers and install drivers myself i found this program could find "all" the ones i could not see. and thus got my gfx card running like a champ a lot quicker than i could. http://albertomilone.com/nvidia_scripts1.html
