If like me you have been fortunate enough to get your grubby mits on a copy of XP service pack 2, and have installed it and been somewhat annoyed to discover the "For testing purposes only. Build 2600.xpsp2.... etc" now loitering on your desktop above the time then you can remove this simply.
Open up Regedit and navigate to the following keys:
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\SystemCertificates\CA\Certificates\FEE449EE0E3965A5246F000E87FDE2A065FD89D4]
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\SystemCertificates\ROOT\Certificates\2BD63D28D7BCD0E251195AEB519243C13142EBC3]
And delete the pair of them, reboot and lo and behold dodgy testing message has vanished!
before making changes to your registry, particulary if you are following someone from the internets advice, make sure your data is all backed up and back up the branch of the tree that you made the changes on before you make them so that you can easily install the bit again. This way saves a lot of tears and tantrums.
This tweaks has not been tested as we do not have service pack 2 beta. Use at your own risk. Be sure to use system restore to back up before applying this.
