I've have with the xp corp. you know the one the was floating around the net. the one that we use to know the serial by heart. the first xp version that was blacklisted
I'm thinking that ms thinks that maybe that one of those copies was pirated or blacklisted, so that they put something in the bootsector to render that computer useless.
you can slave that drive on another machine and use Partition magic secure erase feature (wipe both parts. the unused 8mb part. format it then delete it. and the partitioned part)