Just bought a Geforce GTX 660 and replaced my Radeon HD 5870 (it finally died after 3 years). I'm having terrible problems getting the video card to work. As I only had command line options so far I've ran:
(purged fglrx*)

then

sudo add-apt-repository ppa:xorg-edgers/ppa
sudo apt-get update
sudo apt-get install nvidia-331

and then I started getting low graphics mode errors. did some searching on my tablet, and I tried several things but what finally worked better was:

sudo apt-get install bumblebee bumblebee-nvidia

However now that I'm logged into my computer finally, I have no access to terminal, no access to the top bar, and hitting Super Key does nothing, alt-f2 does nothing, and I only can post because I tried running WoW and it had an error and the error report opened a link.

All I can see on my desktop is my wallpaper and desktop icons. I can CTRL+ALT+F1, and navigate to the downloaded official nvidia driver, however that won't run because of x-server, and I can't run it from my desktop.

Can anyone help me?