Judging from your latest post one would assume you’ve upgraded to a new GPU and not only that you’ve switched manufactures (Nvidia – ATI). So I would recommend the following steps.
• With the 460GTX installed in the pc, uninstalling the Nvidia drivers. • Reboot in safe mode and run DriverSweeper and remove both Nvidia and ATI drivers/directory’s if they still exist. • Then remove the 460GTX and install the 7850 with the latest drivers from ATI.