I have ubuntu 12.04 running on my computer.
Recently, I installed a GTX 690 graphics card and installed the latest NVidia driver (purge the old driver first, then apt-get install). The the computer went to a red screen when it starts.
I can run recovery mode, get terminal with root, then startx/unity. It was okey.
But how can I fix the normal startup? Thanks..
(BTW: I am 100% sure that the hardware is good, I have dual boot with Win7, it works perfectly)