I have a version of Windows XP Pro that my friend's dad gave me because he works at a company with a big network. Well, he gave a lot of my friends it too and we all used Windows Update, and now it says trouble verifying serial when I try to update. On our family computer, it has Windows XP Home, but didn't come with the cd, only a Systemax restore cd. I was wondering if I would be able to change my serial to the Windows XP Home serial, or install XP Home on my computer and use the same serial as my family computer. Would that work? Plus are there any advantages/disadvantages of using Home instead of Pro? I can't tell the difference between the two. And is it possible to install Home over Pro?