if you go to nvidias website .
here , they have a section for linux drivers, you will need to get the i386 version more than likely which is the IA32 link. you will need to reboot your machine and enter runlevel 3 by pressing a key when grub comes up and editing the boot options and adding a 3 to the end of the line separated by a space. then login as root switch to the directory where the binary you downloaded is installed, run it . assuming all goes well you can then edit xorg.conf, you might want to make a copy first. you will need to find the device section and change the driver line from nv to nvidia. you should then be able to boot back into X. oh and you can remove the line load "dri" from the top of the file too
edit: make sure you do copy xorg.conf beforehand
and should X not restart copy it back and repost with what you did
if you don't do this you will have to use another machine or a text based browser e.g. lynx to speak to us