I am absolutely new to Ubuntu and I have a slight problem. After installing it I wanted to get the drivers for the Nvidia 2 Gforce card, I allow the system to search for hardware and it came out with one, which I selected, downloaded and installed. After rebooting, the desktop appears for a quick second and then the screen goes totally black with a working cursor. Any ideas? I tried to open a terminal but it I must have made a typo when I selected a username/password because I cannot login. So...where do I go from here?

HP Pavilion A530E