go to nvida and download drivers using the Manual Driver Search:http://www.geforce.com/drivers
uninstall using Control Panel\All Control Panel Items\Programs and Features
select Nvidia graphics driver and click on uninstall
reboot into safe mode pressing F8 after post and select "safe mode"
run driver sweeper and select Nvidia graphic drivers.
go to download folder and double click the file you downloaded from Nvidia to install.