x server display configuration unable to load x server display

[Valtam]

I take it you have already tried to load a driver? If so you'll need to remove it.
Press: Ctrl+Alt+F1 this will drop you to a tty screen, if you need to, login. Then type in: sudo service lightdm stop
Now do: sudo apt-get remove --purge nvidia-* then sudo rm /etc/X11/xorg.conf
Then do: sudo apt-get install nvidia-current then sudo reboot