Pro Audio Support

Q:
Why is my Windows Multimedia control panel greyed out when I install my M-Audio Duo USB audio interface?
 
A:
You should go into your device manager and delete the WinMM WDM Audio Compatability Driver. Here's how:

Right-click on My Computer, go to Properties - Hardware - Device Manager - Sound, Video, and Game Controllers.

Right-click Microsoft WinMM WDM Audio Compatability Driver, and choose Uninstall.

Reboot, and that should fix it.