Upgrade Win2000 to WinXP

This PC is running Windows2000 and I want to upgrade to WinXP Home SP2. I have the factory upgrade disk from Microsoft, but when I put it in, and click Install, it reports that "this version of Windows cannot be upgraded". WTF?!?!? I read the label on the box and it doesn't mention Win2000, only 98/ME.... does the XPPro upgrade disc work with Win2000??? The PCs owner bought the Home upgrade and told me that the PC was running the "millennium version" of Windows, so I thought it was ME... and, naturally, it's not ME. She doesn't know a whole lot about computers, so she brought the PC and CD to me. Is there a way to still use this Home upgrade with Win2000? She wants to keep all the software intact.... I could have sworn that I've upgraded Win2000 to XP before using an upgrade CD... is my memory really that bad?
Thanks.

 

NT/2000 Pro to XP Pro.

98/ME to XP Home.

Those are the valid upgrade paths.

 

I knew I'd upgraded W2k before! I just freekin' knew it!
Thanks Adryn.... you saved me (again )