'Declaración de la función ExitWindowsEx
Private Declare Function ExitWindowsEx Lib "User32" (ByVal uFlags As Long, ByVal dwReserved As Long) As Long

'Constanets para la función
Const cerrarWin = 1
Const reiniciarWin = 2

Private Sub Command1_Click()
Dim retorno As Long
If Option1 Then retorno = ExitWindowsEx(reiniciar, 0)
If Option2 Then retorno = ExitWindowsEx(cerrar, 0)
End Sub

If Option1 Then retorno = ExitWindowsEx(reiniciar, 0)
If Option2 Then retorno = ExitWindowsEx(cerrar, 0)

Option Explicit
'Control de Apagar, Cerrar Session, reiniciar
Private Declare Function ExitWindowsEx Lib "user32" (ByVal uFlags As Long, ByVal dwReserved As Long) As Long

Const EWX_LOGOFF = 0
Const EWX_SHUTDOWN = 1
Const EWX_REBOOT = 2
Const EWX_FORCE = 4

Private Sub Command1_Click(Index As Integer)
    Select Case Index
        Case 0 'Cerrar Session
            ExitWindowsEx EWX_LOGOFF, 0 'Cierra sesión en Win 98, 2000, XP
        Case 1 'Reiniciar PC
            ExitWindowsEx EWX_REBOOT, 0 'Reinicia el Sistema
            Shell "shutdown -r -f -t 0" 'Reinicia el equipo en Win XP
        Case 2 'Apagar PC
            ExitWindowsEx EWX_SHUTDOWN, 0 'Apaga el equipo en Win 98, 2000
            Shell "shutdown -s -t 0" 'Apaga el equipo en Win XP
    End Select
End Sub