Private Declare Function ExitWindowsEx Lib "user32" (ByVal uFlags As Long, _
  ByVal dwReserved As Long) As Long
 
    Private Const EWX_FORCE = 4
    Private Const EWX_LOGOFF = 0
    Private Const EWX_REBOOT = 2
    Private Const EWX_SHUTDOWN = 1
    Private Const EWX_POWEROFF = 8
 
 
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles Button1.Click
        Dim Retval As Long, MsgResult As Long
 
 
        MsgResult = MsgBox("Wollen Sie sich wirklich abmelden?", _
        vbQuestion + vbYesNo, "Abmeldung")
 
        If MsgResult = vbYes Then
            Retval = ExitWindowsEx(EWX_LOGOFF, 0&)
            If Retval = 0 Then MsgBox("Der Computer kann nicht " & _
            "heruntergefahren werden.", vbInformation)
        End If
 
End Sub