Lost video in Ubuntu?

I recently lost my gui while playing with different drivers. Here is how I got around it.

During the GRUB's boot process press and chose a different kernel to boot from.

At the command prompt, type and login with your user account.

Now type the following:

sudo cp /etc/X11/xorg.conf /etc/X11/xorg.conf.custom
sudo sh -c 'md5sum /etc/X11/xorg.conf > /var/lib/x11/xorg.conf.md5sum'
sudo dpkg-reconfigure xserver-xorg

This will run the script to setup the hardware. Just select the proper driver
and you should be all set.

Thanks to help.ubuntu.com