There is a common fix out on all large trackers, mostly the most well seeded torrent given its small filesize if you know what to search for.
Basically, you change the XP number with it, and then run some WGA-fix, then you have a 100% genuine XP.
No its not some crack that only works 24h, it has been working fine for me for a couple of years even with full updates on. I even prefer it to legal XP since you can mess around with hardware changes etc..
