Private Sub Form_KeyDown(KeyCode As Integer, Shift As Integer)
 
    If Shift = 6 And KeyCode = vbKeyM Then
        If Me.WindowState = vbMaximized Then
            Me.WindowState = vbNormal
        ElseIf Me.WindowState = vbNormal Then
            Me.WindowState = vbMaximized
        End If
    End If
 
End Sub

Mit freundlichen Gr??en,
Andy G.