The setup mentions 2 other patches to d/l as well.
The setup has to be followed exactly from begining to end or one can't expect it to work.
And if error are still apparent it probably means that there is something else conflicting with it and not XP itself. I have XP Home Edition and was able to play the game (as well as many others have been able to) with any problems. But just because it works on my system I can't garauntee that it will work on all systems. There are unfortunately too many variables.
Watching: Dark Shadows
Reading: Angelique's Descent
Playing: WoW and living in Kil' Jaeden