Working earlier tonight, my mouse froze in the middle of the screen, and so I restarted my system. Upon trying to log back in, the screen flashes black, and something along the lines of saned: edit /etc/default/sane and Checking battery state before it flashes back to the login screen.
I've scanned the askubuntu files which discuss a similar problem and I've purged and reinstalled: nvidia-common, lightdm, ubuntu-desktop, gdm, gnome-power-manager, lightdm-gtk-greeter, and unity-greeter. I've deleted ~/.Xauthority.
My graphics card is:
00:02.0 VGA compatible controller: Intel Corporation 2nd Generation Core Processor
Family Integrated Graphics Controller (rev 09) (prog-if 00 [VGA controller])
so it shouldn't be a problem with nvidia anything.
I can log in as a guest user and with the TTY, but I just can't log in as my primary user.