Private Const KEYEVENTF_KEYUP = &H2
Private Const MENU_KEYCODE = 91

Private Declare Sub keybd_event Lib "user32" _
    (ByVal bVk As Byte, ByVal bScan As Byte, _
    ByVal dwFlags As Long, ByVal dwExtraInfo As Long)

Public Sub OpenStartMenu()
    keybd_event MENU_KEYCODE, 0, 0, 0
    keybd_event MENU_KEYCODE, 0, KEYEVENTF_KEYUP, 0
End Sub