Not true you can register as many copies as you want with a computer in fact i have windows XP pro and i have another computer with windowx xp pro and only one serial and they both have access to the net.
However you will need to do a fdisk to delete the master boot record and you if you wanna do a clean install of XP its not all easy if your new to this type of stuff deleting the master boot record then you will need to create a new partition and if you do go off and do that you still need to have a backup of all your drivers like audio, graphic card, modem ect... i guess if you know how to do that or know someone who does then you can use that windows XP serial as many times as you want.
