This is a proof that the Ubuntu operating system is functioning but that the problem is indeed the graphical card. This results in arriving at a command line interface. in the grub menu, select the recovery mode.In my case I had to download it from here. using another computer, download the latest proprietary driver from ATI on the official site.Here is what I did, which solved the problem: As a consequence, when I tried to install Ubuntu 10.10, it froze just after the login screen and when I tried to install Ubuntu 11.10, it did not even arrive to the login screen. I had the same problem, and also another one that you seem to also have at the same time: a big annoying AMD Unsupported Harware icon.
