I've got a counterfeit copy of XP Pro. Given the exorbitant price Microsoft wants for one of their kits to correct the problem, I'm tempted to pick up a copy of XP Home while it's on sale at Wal-Mart. Can I install it over my XP Pro, or do I have to uninstall the XP Pro first? I know this is a basic question, but I really don't want to screw up my computer doing this. Thank you in advance.