Try doing 'sudo dpkg-reconfigure xserver-xorg' and answer the questions in the menu as they apply to you. When it asks which display driver to use, select fglrx. Once you're done, reboot and test. If everything works, the command 'fglrxinfo' should list strings about ATI, Radeon, and OpenGL, and the driver version.
If the above instructions still do not work, it may be helpful to post any error messages. In that case, run 'dmesg | grep fglrx' and copy the output (if any) here. -- No direct rendering for ATI Radeon Xpress 200M https://launchpad.net/bugs/62538 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
