My Computer, Win Explorer won't start

Hi! when trying to start Windows Explorer or My Computer, the screen goes blue, then the desktop returns. Anyone with a fix?
Many thanks, Agi

What computer?
What specs?
What windows?

Hello Ferrit,
ASUS M389
Intel P4, 800mHz
1G SDRAM
Don't know what the hard drive is, but about 80G, 7200rpm (it's my friend's computer, I am trying to help her...)

Can you launch Windows Explorer Manually by launching explorer.exe through windows task manager? Can you get into windows in safe mode? I have seen pcs with similar symptoms infected with spyware that can cause this.