Possible Duplicate:
How can I control the audio volume of a Modern-UI application?
In Windows 7, you could volume mix programs, using the built in volume mixer:
In windows 8, you can access the mixer in exactly the same way as in 7, on the desktop, but from here you can only mix desktop apps.
However, I cannot find a way of volume mixing Metro apps.
How can I volume mix Windows 8 Metro apps?