My computer starts up and you see the generic UBUNTU loading with the dots underneath and instead of going to a login it takes me straight to a Firefox window where i can not do anything. The computer is a ThinkCentre M55e (type 9637) that i received from a school as they where going to throw them out. I don't know the version of Ubuntu or much about the program itself, so some help would be much appreciated. I assume the lack of ability was to stop children from playing around on the desktop.