mup.sys startup issues

I have read a lot of threads on this topic and all of them are different. Let me tell you about my problem. I am using a Sony Vaio Laptop and am running XP. The problem started the other day when I was using the computer and the mouse stopped working and then the screen went blue. So i restarted thinking that would solve the problem and the computer just hung up at the welcome screen. Then I tried running in safe mode and it stopped at the mup.sys. Sometimes I can get it to start up while using Last Known Configuration but even when that works it takes a while to get on the computer and both the mouse and the keyboard down work. I did a complete system restore and that has not solved the problem. Anyone have any other suggestions??? Thanks