Uninstall ATI driver
$ sudo sh /usr/share/ati/fglrx-uninstall.sh (if file is existing)
$ sudo apt-get remove --purge fglrx fglrx_* fglrx-amdcccle* fglrx-dev*
Install free driver
$ sudo rm /etc/X11/xorg.conf
$ sudo apt-get install --reinstall libgl1-mesa-glx:i386 libgl1-mesa-dri:i386 xserver-xorg-core
$ sudo dpkg-reconfigure xserver-xorg
Reboot
$ sudo reboot
Download ATI driver
$ mkdir ~/catalyst12.6/
$ cd ~/catalyst12.6/
To know what Graphic Card you have, do lspci -v | grep -A 12 VGA
. Download the appropriate driver for your machine here from the AMD/ATI Website.
File should be something like amd-driver-installer-12.6-legacy-x86.x86_64.run
(not version 12.04 like in previous answer, 6 months earlier). Move it in ~/catalyst12.6/
.
Unzip it if needed.
$ unzip amd-driver-installer-12.6-legacy-x86.x86_64.zip
Install ATI driver
$ sudo apt-get install build-essential cdbs dh-make dkms execstack dh-modaliases fakeroot libqtgui4
$ sudo chmod +x amd-driver-installer-12.6-legacy-x86.x86_64.run
$ sudo sh ./amd-driver-installer-12.6-legacy-x86.x86_64.run --buildpkg Ubuntu/precise
$ sudo dpkg -i fglrx*.deb
$ sudo amdconfig --initial -f
Reboot and Check if installation is successful
$ sudo reboot
$ sudo fglrxinfo
display: :0 screen: 0
OpenGL vendor string: Advanced Micro Devices, Inc.
OpenGL renderer string: ATI Radeon HD 4200 Series
OpenGL version string: 3.3.11653 Compatibility Profile Context
It is all good, as you can see, after last reboot, fglrxinfo displays my ATI Graphic card correctly.