If you go over on nvidia forums there are tons of people who are nor being able to install the driver.
the probable solution to the problem was posted there on nvidia forums by the real hotshot
"Did you set CWDIllegalInDllSearch=FFFFFFFF in [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\ Session Manager]?
Delete it temporarily and try again... "
This seems to have solved the problem for most people