There are quite a few things that should be checked before upgrading to a new operating system. Microsoft has a few Knowledge Base articles about the upgrade to Windows XP. Below are just a couple:

Troubleshooting WinXP Setup Problems When You Upgrade
http://support.microsoft.com/default.aspx?scid=kb;en-us;Q310064

Release Notes for WinXP Pro Version
http://support.microsoft.com/default.aspx?scid=kb;en-us;Q286463

Release Notes for WinXP Home Version
http://support.microsoft.com/default.aspx?scid=kb;en-us;Q306824

Thanks for the tip.

Grif