I just built a new computer for my daughter. I installed the xp disc from my computer just to make sure everything is working right. I ordered a new xp disc for her computer, it isn't here yet. She doesn't want to wait the week it will take to get the new disc to get her computer back. I don't want to go to the hassle of loading in all her software, just to reinstall it all again when the new xp disc gets here. my question is When the new disc gets here can I activate her windows from that product code even though I installed from a different one. I am sorry this kind of sounds confusing, if i can make anything more clear, please let me know.

I dont think that is possible because when you install XP, it puts this long number that you have to supply to Microsoft to activate Windows. Now since you installed yours, your number is on her computer, so when you call or go online to activate, it will give you your number to give to them, and so it'll be like trying to activate yours again. She can stay on your 30 day activation limit, and maybe there is a way to install her disc over your copy on her computer without trashing her software and hardware settings.

As long the one you got is the legal version, which is under your name. And after when her cd arrived you then can reactive with her product number. -=Art=-

You can do whatever you want. Either re-install from new CD, or change serial no to activate (which I think this is really whay you're looking for). Please go to http://homepage.ntlworld.com/grant2k/ewhb/TUT_serial.htm UK

Is there a way to change serial number in XP? If there is that would be perfect. Then you could just change it to hers and activate it then.

When you go to activation your XP there is an option to 'Change Product Key' so just enter that new key from your new disk then activate

all you have to do is call the activation hotline and tell them that you had to reinstall your OS. I work at the place where they do the activations.