Public Sub ProcessDirectory(ByVal targetDirectory As String)
        Dim subdirectoryEntries As String()
 
        Try
            subdirectoryEntries = Directory.GetDirectories(targetDirectory)
        Catch ex As Exception
            Dim strBox As String = "Verzeichnis: " & targetDirectory & " ist" & _
              "nicht vorhanden!"
            strBox &= Chr(13) & "Bitte überprüfen!" & Chr(13) & "Programm wird" & _
            "beendet!"
            Dim strMsgAntwort As String = MessageBox.Show(strBox, "RW Backup -" & _
            "Fehlermeldung", MessageBoxButtons.OK, MessageBoxIcon.Stop)
            End
        End Try
 
        ' Diese Prozedur rekursiv aufrufen
        Dim subdirectory As String
        For Each subdirectory In subdirectoryEntries
 
            frm_Main.ListBox1.Items.Add(subdirectory)
 
            ProcessDirectory(subdirectory)
 
        Next subdirectory
 
 
    End Sub