Visio 5 and Windows XP

I loaded Visio Professional version 5 onto a Wnidows XP SP1 machine and when I start Visio, it displays a message, "Visio is incompatible with this version of Windows. For more information, contact Microsoft."

I can find no information on the Microsoft as to why there is an incompatibility or what it might be.

Can anyone tell me what is happening and why? Visio seems to operate correctly.