Ubuntu live-cd gets stuck on vista, though it works well on xp

My question is similar to a lot of the vista problems in that the live cd works great on my windows xp computer but wont work on my dad's vista. I've read that the operating system doesn't affect the live cd and I've pressed f10 and put my disk drive at the top for the BIOS order. A description of what happens is that when I start up my computer I'll see the name Ubuntu and the little dots underneath lighting up in turns, then it seems to freeze and never goes on to the desktop or even ask me what language and if I want to use it without installing. The closest I ever got was after pressing f2 somehow I got the language option and selected use without installing but the same freezing happened. I really hope I can get Ubuntu to work on this computer! could it be that its because this computer is really slow and possibly has a virus?
thank you