Muting other applications, then playing a sound

Hi,

I'm trying to make an application that mutes other applications, plays a sound, and exits.
Been trying to use DirectSound, but if I take control of the primary buffer I can't use secondary buffers and I can't manage to play a WAV/MP3 file.

Please help.

And why would you need to "mute other applications"?

I'm intrigued to know too. A can only think that your application is responsible for detecting incoming missiles? If it is, then a better idea would be to run it on it's own computer or 3.

EDIT: And wire up some bigger speakers.