Does nothing, it's not my computer as said this only happens when playing RoM when I alt+tab to test my sound my sound works fine but for some reason the SFX and Game Sounds just drop.
Not quite sure what you mean here. If you mean sound dropped & nothing will bring it back it could be a driver issue. I've helped several friends get their in-game sounds working. All had AMD comps with Realtek chipsets, a simple driver update fixed it.
If you mean some sounds stop working after a short time playing, join the club, that is just the notorious RoM memory leak that most of us eventually learn to ignore. Restarting the client usually brings them back for a while.