You would want the upgrade. BUT, XP needs a pretty decent machine to be run on. Yours sounds like its a little on the old side.

Windows XP Upgrade Advisor

"Microsoft posted their Windows XP Upgrade Advisor tool for download on their Web site. The Upgrade Advisor is a tool that checks your system hardware and software to see if it is ready for upgrade to Windows XP. If you run Upgrade Advisor while you are connected to the Internet, and if your system needs updates that are available on the Windows Update Web site, Upgrade Advisor will find and install the updates for you. "

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