www.gog.com or Origin got sell..

or try War for the Overworld on Steam : http://store.steampowered.com/app/230190/ (the spiritual successor)

free version you'll need to dig around the internet for it..

Game play and mechanics very similar. They trying to be as close as DK2 but not to be an exact clone.
Names of minions are different but its more or less the same thing with a lot better graphics.

But do note, this game is still quite buggy. The devs are constantly fixing and improving it, but still has weird quirks from time to time. Still a playable game tho. Worth a try but better buy during a steam sale.