Thanks you for your swift reply.
I pressed 'Ctrl-Alt-F2' to exit X (Hope that's correct)
Here's what I got, when I entered as root:
bash: pico: command not found
So, I used 'vi' for editing XF86Config
In section: "Device" I replaced "nv" -> "nvidia"
Did not find the line: load "dri" though.
(I noticed there is a line that contains: 'glx', should that stay?)