Possible Duplicate:
My computer boots to a black screen, what options do I have to fix it?
I have an nvidia geforce 295 GTX, and it works great in Windows.
However, when booting into Ubuntu I had intermittent problems for a while where the system theme went haywire, it looked like "windows classic" with gray windows et cetera. Then they stopped being intermittent, and I always had these boring gray windows. I tried finding a workaround uninstalling the nvidia drivers and downloading newer ones from Nvidias site.
I uninstalled them but couldn't shut down the xserver to command line. If I did /etc/init.d/gdm stop
the system just hanged. I tried booting into recovery mode, but after a whole bunch of startup output my screen goes to sleep (eg no output).
Lastly this has escalated so now I don't get any image when I boot into a normal Ubuntu session