
The computer is an HP Pavilion laptop running windows xp sp2.
When I turn on the computer, it brings up a black and white menu screen telling me that windows could not start in normal mode, and asking if I want to start in safe more or from the last working settings. Every time I pick one of these options, windows starts to star, and then the computer restarts.

I made a UBCD and have figured out how to use it (more or less) with the computer. I was thinking that perhaps I have a virus, so I've tried the various virus scanners that come on the UBCD. Some of them find nothing, but 2 of them start to scan, and then restart the computer in the middle of the scan.
Does anyone know what is going on? Is this a virus, or maybe something else? If anyone knows, I would very much appreciate some help.
(PS... I don't really know what any of the other stuff on the UBCD is, so perhaps there's something else I could use besides the virus scanners to figure out the problem?)