no it's not legal. the windows license states a end-user can install a copy of windows on both their laptop and desktop, BUT you cannot be using both at the same time. Carlo when your dad tries to activate the same product key 6 times in such a short time, the microsoft girls will start getting suspicious. I think it used to be that instead of buying full copies of winXP you could buy OEM product keys from online stores at a fraction of the cost for a full copy of winxp. I think microcrack have disabled OEM keys though