Posted 26 March 2006 - 03:27 PM
How did it already have Windows installed?
If it was installed on a different computer it will have an incorrect registry for the one you put it in, and besides, XP won't recognize the installation as legitimate either. It isn't the computer that XP was licensed in.
If your original installation of XP was installed using a retail version CD, you may be able to reauthenticate it, but you will have to either reinstall it on the new hard drive using the retail Windows CD (and the 25 digit key number that came with it) or migrate it from the old hard drive using migration software.
If it came preinstalled in a different brand name computer and you don't have a retail Windows XP installation CD (and the appropriate 25 digit key), the license is not transferable.
(i.e. If it came preinstalled in a Dell computer and now you are trying to put it on a different computer even if it is another Dell.)
The way you install a new hard drive is to put your old one back in and then use the software that came with the new hard drive to transfer everything to the new hard drive which must be installed as a slave to recieve the migrated data. Once that is accomplished you can install it as the master and remove the old drive or use the old drive as a slave.
Make sure the jumper settings on the hard drives (both) are installed properly as master or slave (and reset when you move them).
If you don't have the migration software you can download it from the new HD manufacturer's site - i.e. Maxblast for a Maxtor drive, Seatools for Seagate, etc.
If you are trying to pirate XP, you will most likely not be successful. If the 25 digit license key has ever been used in any other computer, it will not activate in yours.