The problem is the login screen is divided into two showing a onscreen keyboard like thing in the left side and the same magnified in the other side. Also it is giving the error message as /usr/lib/libgconf2-4/gconf-sanity-check-2 exited with status 256
Recenly a friend of mine reported a similar problem which was due to "mistakenly" turning on the
screen magnifier
andon-screen keyboard
from the accessibility preferences. Apparently this is a known bug.If this is (a part of your problem) you can try out the fix recommended here.
Assuming that you do not wish to actually uninstall the screen magnifier or on-screen keyboard, here are some commands to disable them in GDM.
If you are able to log-in to the desktop, you can run them from a terminal or press
Alt-F2
to get the run dialog, check "Run in terminal" and enter the commands there.If you can't get to your desktop, press
Ctr-Alt-F1
to drop to a console, login, enter the commands. You may have to restart to see the effects.Disable screen magnifier in GDM:
Disable on-screen keyboard in GDM:
Run
sudo killall magnifier
from a terminal (or a tty if you cannot login), return to the login screen and deselect the magnifier option.