Change default audio device on Windows 7

A little up-to-date answer, which is compatible with Windows 10.

This program is able to do it in a beautiful manner (hotkey to switch between pre-selected devices) and is written on C# : SoundSwitch on GitHub

Some reverse engineering should get you there (for my use this program was just perfect as it is).

It makes use of that library (same author) which is in C++ : AudioEndpointLibrary on GitHub

So if you know C++ (which I don't enough), you might go further in the analysis of how it works. Or just use the library like SoundSwitch does.

Just in case anyone stumbles across this thread in the future... here's some C++ code that'll do it by calling some undocumented Win32 APIs. This can be compiled into an EXE and then called silently from a .NET application, so you could build a .NET program around this code.

http://web.archive.org/web/20190317012739/http://www.daveamenta.com/2011-05/programmatically-or-command-line-change-the-default-sound-playback-device-in-windows-7/