You installed the proprietary fglrx/Catalyst driver, which does not support your card. Use the commands below to fix the issue.
sudo apt-get remove --purge fglrx fglrx_* fglrx-amdcccle* fglrx-dev* sudo apt-get install --reinstall libgl1-mesa-glx libgl1-mesa-dri xserver-xorg-core sudo mv /etc/X11/xorg.conf /etc/X11/xorg.conf.backup sudo rm -rf /etc/ati Now, reboot the system. ** Changed in: xorg (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xorg in Ubuntu. https://bugs.launchpad.net/bugs/1004815 Title: graphic driver problems To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1004815/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp