ok then. download the nvidia installer here
The instructions I'm giving is also available here
so you can follow along if you wish.
first thing to do is dowload the file.
second : kill the x server. get a bash prompt and as su : telinit 1 (that should get you a prompt
try out different runlevels if that doesn't work. There is a readme file in your /etc/init.d telling you all about how the systems boots and the runlevels. Any runlevel without x running should work tho.
with no graphical interface)
third navigate to the nvidia file.
four type : sh nvidadrivername.run
just follow the directions on screen.
root privileges is a must on this install