My laptop wil not start.

Hello,

I was on the internet, and listening to a song on youtube and my computer froze. So I turned off my computer, and now when I turn it on it comes up with the selection on how to start (normally or in safe mode). Whenever I try to start normally it comes to the screen where it says Windows and has the bar moving across it, and it stays like that until I turn it off. Whenever I put it on safe mode it stops on the one that says "Drivers\Mup.sys" and it stays like that until I turn it off. What should I do? (If it matters I have Windows XP, and my internet is Firefox.)