If these are the Windows XP cd's that come from Dell ( Dell insig on cd ) You can install them on another DELL machine without being prompted for the activation code.
During installation it does some verification on BIOS to see if its a Dell machine.

Now if you take that same Cd and load it on an IBM it'll prompt for serial key etc..
If you need Win XP SP2 Pro let me know. I have a crap load of those disc's laying around.