If you've been reading this blog for long, you know what a sucker I am for ThinkPads. I buy them off lease from RetroBox. If you watch them closely (think every day), you can really find some good deals.
They come from RetroBox wiped clean; no OS. That always gets me to scrambling even though they all have a Certificate of Authenticity (COA) for Windows XP Pro on the bottom with a key. You'd need the IBM OEM XP Pro recovery CDs to use this key. Or so I thought.
Tonight I found the way to activate using this key. I have a consumer media for Windows XP Pro with a key. Use this and do a normal install even including entering this key. Don't sweat it if it has already been activated.
Then after the install is complete and before activating, go to Microsoft and download the Windows Product Key Update Tool. Run it and follow the instructions using the key on the COA on the bottom of the ThinkPad. One reboot later, you're done. It's even authenticated!
I don't see why this wouldn't work on any PC with an OEM COA. Let me know your experience.
I found this technique here on My Digital Life.