Sorry, but you're out of luck....
It's always been this way with Microsoft Operating Systems...... one purchase of
the software is licensed to one computer only. If you wish to install it on a
second computer, it can, but must be completely removed from the first computer.
Windows XP just enforces this with product activation, which licenses it to that
computer only.
Doesn't matter which version you want to use... XP Home and XP Professional are
licensed to one computer only. If you want, you can purchase one software
package, and then contact Microsoft to purchase additional licenses (and obtain
new product key's for each license).
The additional licenses cost slightly less than the full software package
(emphasis on "slightly"), but at least that will save you a little bit of
money...