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
This may and may not help depending on your computer. I recently tried to upgrade a friend's Gateway computer from Win ME to WinXP. Computer started the install then locked-up. Finally after about 5 tries called Gateway tech support. After discussing the problem I found out the computer didn't have enough memory for the upgrade. Check to see how much memory you need for the new WinXP Pro AND all the applications you will be running at the same time. Extra memory will also give you a performance boost and possibly avoid future lock-ups. From a value viewpoint it is also probably the single best way to speed up your computer.

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