When you try to upgrade to Windows XP Professional, from Windows 98, Windows 98 Second Edition, or Windows Millennium Edition, you receive:
Setup cannot upgrade your current installation to Windows XP. Your copy of Windows XP does not support upgrading from an evaluation copy of Windows. Setup cannot continue.
The above error is misleading. It will occur if you attempt to upgrade an OEM (Original Equipment Manufacturer) version of the above operating systems to Windows XP Professional AND you are using an OEM Windows XP Professional CD-ROM that is designed to upgrade an OEM version of Windows 2000 Professional.
Contact the OEM that provided your Windows XP Professional CD-ROM and ask for the CD-ROM designed to upgrade your particular operating system.