Try going to
http://www.nvidia.com.
Download the latest linux driver for your graphics card.
It should be named something like: NVIDIA-Linux-x86_64-169.12-pkg2.run
Set the permissions on this file..
me@donkey:~# chmod +x NVIDIA-Linux-x86_64-169.12-pkg2.run
Then run it..
me@donkey:~# ./NVIDIA-Linux-x86_64-169.12-pkg2.run
Then just follow the on-screen prompts.
If Nvidia moans that it cannot find your kernel headers, You will need to install it.. So do the following:
Check what kernel version you are currently using..
me@donkey:~# uname -a
Linux donkey 2.6.24-16-generic #1 SMP Thu Apr 10 12:47:45 UTC 2008 x86_64 GNU/Linux
Get the kernel-headers package
me@donkey:~# apt-get install linux-headers-2.6.24-16-generic
At the end the Nvidia driver will update your xorg.conf file ..
After that try running startx hopefully it will work if not u might have to make a few changes to the xorg.conf.
You can change the resolution by updating the xorg.conf or using the Nvidia Control panel thing when Gnome/KDE is running
-Rich