1.Private Const APPCOMMAND_VOLUME_MUTE As Integer = &H80000
2.Private Const WM_APPCOMMAND As Integer = &H319
3.Declare Function SendMessageW Lib "user32.dll" (ByVal hWnd As IntPtr, ByVal Msg As Integer, ByVal wParam As IntPtr, ByVal lParam As IntPtr) As IntPtr
4.
5.Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
6. SendMessageW(Me.Handle, WM_APPCOMMAND, Me.Handle, CType(APPCOMMAND_VOLUME_MUTE, IntPtr))
7.End Sub
