This happened to me recently when I installed some updates via synaptic. I rebooted and it went to low graphics mode because X decided to overwrite (i assume) my conf file that WAS working just fine.
I fixed this problem by manually editing xorg.conf to the following values. I was able to boot into gnome but then I exited to the prompt via alt+cntrl+f3. Section "Device" Identifier "Nvidia Geforce 6600" Driver "nvidia" EndSection -- GeForce 6600 not supported https://bugs.launchpad.net/bugs/313306 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs