<p>Anyone know how to programmatically mute the Windows XP Volume using C#?</p>

Declare this for P/Invoke:
```
```
private const int APPCOMMAND_VOLUME_MUTE = 0x80000;
private const int WM_APPCOMMAND = 0x319;

[DllImport("user32.dll")]
public static extern IntPtr SendMessageW(IntPtr hWnd, int Msg, IntPtr wParam, IntPtr lParam);
```
```
And then use this line to mute/unmute the sound.
```
```
SendMessageW(this.Handle, WM_APPCOMMAND, this.Handle, (IntPtr) APPCOMMAND_VOLUME_MUTE);
```
```