Nvidia driver problem

Sat Oct 1 00:57:34 UTC 2011

I tried sudo nvidia-xconfig and I get this which I already know

Using X configuration file: "/etc/X11/xorg.conf".

VALIDATION ERROR: Data incomplete in file /etc/X11/xorg.conf.
                   Device section "Default Device" must have a Driver line.

Backed up file '/etc/X11/xorg.conf' as '/etc/X11/xorg.conf.backup'
New X configuration file written to '/etc/X11/xorg.conf'