Do it from the command line (ie not in gui mode), as root, run:
You go through some dialogs that set various graphics settings. You'll need to know your monitors horizontal and vertical refresh rates, and I'd use option 18 "nv" for your video card when you get to that part. That gives you a basic XF86Config to work from. From there get the proper nvidia drivers, install them, and edit XF86Config again (by hand, there are instructions on what you have to alter in the readme).