Ok ive asked this question before but never got a proper definate answer for it, at the moment i have a fujitsu-siemens computer with a full xp restore disk, at the moment when i reinstall with it on the current computer i am on, it does not ask me to activate it, i even installed it on another hard drive (on the same comp)still didnt ask me, so im assuming theres a code written somewhere on the motherboard, but thing is my new motherboard is arriving tomorrow, and before i install it i need to know a few things, the new motherboard has the same chip ie: i915p so do u think i will have to reinstall windows again, and also i have a feeling cause ive changed motherboards if i do need to reinstall its going to ask me to enter the license key to activate it, i have a license key on the fujitsu-siemens case, will that work, and if it dont, am i within my rights to phone microsoft and ask them to give me another one, even though i have changed the original motherboard, thanks in advance. 
Lisa
Lisa