Dungeon Keeper 2 installs fine, but when trying to play the game everything is slow, and there is no sound.

The few things I have tried are

Reinstalled the game.
Ran safe mode
VSync is on
Tried Compatabilty mode

Now I don't know if the game is still getting updates or not, but I tried enough things with no luck. Not many videos on youtube about it ether.

I'm not sure about the sound problem, but about the performance issue I think you should watch this video.
Basically you should download this archive and extract it into the game's folder.