The display problems in linux occur mostly due to misconfiguration of X-server config file (xorg.conf) this may happen when you install or update graphics driver for your display card or due to various other reasons.

So to troubleshoot GUI display problem just follow these steps:
  1. Login as root
  2. At the shell prompt navigate to /etc/X11 directory (cd /etc/X11)
  3. Copy the failsafe configuration file to original file
    "cp xorg.conf.failsafe xorg.conf"
  4. Start the x-server
The aforementioned steps should resolve the display problems :-) .