i have the same problems like you!
i recently realized, that all new games suck und remembered my glorious childhoud games -> dungeon keeper 2
and wanted to play it again......
the fact is:
The game worked on this computer before. (with older drivers and without any service pack and with less HDDs, but this fact doesn´t count )
That means sp2 or the new graphic driver are the meanies, that keep us from playing!