VB - 2000 / 2003 / XP / Vista Installationsschlüssel auslesen

Public Function sGetXPKey() As ListViewItem
        
        'Registry öffnen und Wert auslesen (byte array) 
        Dim RegKey As RegistryKey = _
        Registry.LocalMachine.OpenSubKey("Software\Microsoft\Windows NT\CurrentVersion", False)
        Dim bytDPID() As Byte = RegKey.GetValue("DigitalProductID")
        'Nur die benötigten Teile ins Array laden
        ' Key beginnt ab byte 52 und ist 15 Bytes lang.
        Dim bytKey(14) As Byte '0-14 = 15 bytes
        Array.Copy(bytDPID, 52, bytKey, 0, 15)
        'Unser "Array" beinhaltet nun  gültige Zeichen
        Dim strChar As String = "BCDFGHJKMPQRTVWXY2346789"
        'jetzt muss der decodierte Schlüssel zurückgegeben werden
        Dim strKey As String = ""
              
        For j As Integer = 0 To 24
            Dim nCur As Short = 0
            For i As Integer = 14 To 0 Step -1
                nCur = CShort(nCur * 256 Xor bytKey(i))
                bytKey(i) = CByte(Int(nCur / 24))
                nCur = CShort(nCur Mod 24)
            Next
            strKey = strChar.Substring(nCur, 1) & strKey
        Next
        'nun muss das Ganze in einen String eingestzt werden.
        For i As Integer = 4 To 1 Step -1
            strKey = strKey.Insert(i * 5, "-")
        Next


        Dim strPName As String = RegKey.GetValue("ProductName")
        Dim strPID As String = RegKey.GetValue("ProductID")

        Dim lvi As New ListViewItem
        lvi.Text = strPName

        Try
            lvi.SubItems.Add(strKey)
        Catch ex As Exception
            lvi.SubItems.Add("n.a.")
        End Try


        Try
            lvi.SubItems.Add(strPID)
        Catch ex As Exception
            lvi.SubItems.Add("n.a.")
        End Try

        RegKey.Close()
        Return lvi
    End Function