I had the same problem with my geforce 6800 256mb. Your Nv4_disp.dll file has been corrupted by installing a newer or older update without properly unistalling all or your old drivers. It is very simple to fix this issue. But first you will need to download a program called "
DRIVER CLEANER PRO". Once you download this program it will include very detailed instructions on how to remove all the corrupted NV4 files. Very simple to use. Email me with any questions. You can get this program from "
www.download.com"
goodluck