you have no configuration of your video card of course, it has detected the name/brand but the drivers are not correct.....
As i suggested to may other people who had the same problem, put VESA as a driver in your xorg.conf and you will have your gui able start with generic linux drivers. Then later you can take a look to your proper drivers.
do you guys find this that difficult to do?
it is very basic and i don't really understand what is the problem in knowing such thing....
it is also obvious and known to everybody (all linux user's I'd say) that the live distro are starting with vesa driver, that is why you can have the DM starting with live cd without issues.
come on and do your homework...