Reinstall XP Pro, But NOT Upgrade

Hi. I am trying to Reinstall XP Pro, but it is not an upgrade. When I begin, I get a message saying the version is older than the one that's on there, so it won't let me do it. However, the compueter is so slow and bogged down, and I want to give it away to someone with a fresh copy of XP pro on it, btu I am not allowed. How do I do it?

Can I delete XP Pro and then reinstall it? What?

 

http://support.microsoft.com/?kbid=316941

You are getting that message because the version on your hard drive is of a higher service pack level than whats on the CD.

You can do a clean install, or remove the service pack.