You stated you 8600 in onboard is should be a card, is that correct.
TorrentG is correct with the .inf file but Nvidia immediately starts the install.
Download the .EXE, use Universal Extractor | LegRoom.net to extract the file the look for the .inf file and go through Device Mab ager to update driver
In Universal Extractor, it places a UniExtract entry on the right-click context menu.
Also only check the first box when installing
My Computer
At a glance
Windows 7 Pro & Vista Home PremiumAthlon 64 3800+ (Orleans) 2.40GHz2GB DDR2 RAM DIMMNVIDIA GeForce 8500 GT 512 MB memory HDMI out