I've been trying to install the linux ATI drivers for my Radeon 9600 video card. I've figured out how to get to the location of the download through the BASH prompt however when I try to follow the instructions here
I get a message saying that the user myth cannot run so and so. My question is how do I change to the root user? and can i do it through the bash prompt? If not how do I get under the GUI to do this? Every time I try to get out of the gui Mythtv just restarts.

Please try and keep it simple as this is the first time I've run linux

See the LinuxTips Page on the KnoppMyth Wiki. http://www.knoppmythwiki.org/index.php?page=LinuxTips