Windows XP SP1 & ADMINPAK B3
The ADMINPAK B3 version is incompatible with the recent XP SP1 release.
Unfortunately MS does not note this.
Once SP1 is installed you can not uninstall the ADMINPAK B3.
I received a message Service Pack level mismatch and it dies.
You must use MSIZap and edit the registry to remove.
Enjoy ... 