I bought an old IBM Thinkpad T42 some while ago and installed XP SP2 from a CD. A few days ago I fitted a new, larger HDD and decided to load a fresh XP SP2 from the same CD.

Having formatted a large NTFS partition, on the next bootup, with the CD still in the drive, I had the message that XP was already loaded. OK I thought, perhaps I wasn't paying attention.

On proceeding to install XP as I had done before, on completion the installation never asked me for the installation key as it should have done or even to register the copy with Microsoft. Magic!

Has this range of laptops a secret store somewhere so it remembers previous installations?