My friend has a monitor trouble, and i need help on this...quote form him

the best way to describe this is that my display screen's done a cut and paste on itself like parts of the screen have been literally ripped off and placed somewhere else
No magnets have been near it according to him, and he thinks its a WinXP problem though i am not sure. His comp he says is slowing down even with defrag...any clues tips...or anything?