I’ve had a problem with sound not working for windows 7 for a while.
Couldn’t find help on the forums, so now that I got it back I figured I should post the fix here. 
Press F1
Go to options > Audio
play a midi (Don’t know if it’s required)
(If you’re new and don’t know what a midi is you can write in stef1.mid)
change the midi volume
Now sound should work again.