trying to turn off 3D audo acceleration

[shant]

so i just installed the good old might and magic 7, it has some problems on windows 7, the audio hangs, i researched a bit and found out that if you go to the installation folder and run the game setup, you can turn off accelerated 3D audio and that fixes it, the problem is that i can't turn it off because it option is grayed out, any idea why that might be? is there an alternative way to force and turn it off ?