Are you sure the sound driver is the problem? Try using a different CD rom if you have one. It may be you need analog sound. Usually when you have two drives, only one is hooked up for this.
Okay, after three years of trying everything and not having a solution.
Someone actually manned up and did the required thing. A server to play music accordingly to the game.
Meaning it's another program that you run while running Heroes 2 and it will play the proper songs at proper times. In stereo with opera.