Sound in-game problem

[Mahmoud Ahmed]

I was playing red alert 2 for 14 years and mental omega 3 years ago, for the first time the sound stopped suddenly inside mental omega , but still run in the lobby and also in red alert 2,

I reinstalled mental omega many times and still have the same problem, lobby sound is intact, but inside the game, both sound and music was lost

I Put the files as every time before. this's the strangest problem I found here 

What shall I do ?!!