XP Pro

and what happens if i keep it on my old laptop?

i have bought xp pro and installed it to my laptop im using now so what i thinking you are saying is that if i buy another laptop and install xp pro i must or should take it off my old laptop?

i guys um im confused but i have bought a xp pro software and i have installed it to my laptop and now im thinking of buying a new laptop but can i install xp pro again?