My sister-in-law had a Compaq PC. I have a Compaq laptop. I reinstalled XP on her
PC using my Compaq OS disk. It installed just fine but the code-key didn't work.
She had to go out and buy a new XP OS CD. I used the code key from that and everything
worked just fine. Neither Microsoft nor Compaq were willing to help to make the genuine
key on the computer work!