I installed Ubuntu 11.10 today. Everything went fine. But when the system starts up, I cant see the Log in screen. I just see a pink screen. If I type the password, i hear the sound of the logging in, but the pink screen remains.
Previously I had an Nvidia 9400GT graphics card. It worked well. Now i upgraded the graphics card to ATI Radeon 6850. I can no longer use ubuntu. Have tried reinstalling ubuntu so many times. It doesnt seem to work.
What should i do to solve this problem?