I want to point out immediately that I do not want the level, every answer I've seen so far has to do with people wanting the level so they can make meters. I need to find out how to get the system volume.
The closest I have come is using this pinvoke
[DllImport("winmm.dll")]
public static extern int waveOutGetVolume(IntPtr hwo, out uint dwVolume);
But that only gets the audio of my application, I need the "master" system volume.