Public Class Form1
'Hashtable erzeugen
    Private has As Hashtable = New Hashtable
    Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) _
      Handles Me.Load
        Dim i As Integer
'Hashtable mit Strings füllen
        For i = 0 To 10
            has.Add(i, "AAA" & i.ToString)
        Next
    End Sub
 
    Private Sub Form1_Shown(ByVal sender As Object, ByVal e As _
      System.EventArgs) Handles Me.Shown
        Dim i As Integer, b As String = ""
'Inhalt der Hash Table anzeigen
        For i = 0 To 10
            b += has(i) & vbCrLf
        Next
        TextBox1.Text = b
    End Sub
 
    Private Sub Button1_Click(ByVal sender As Object, ByVal e As _
      System.EventArgs) Handles Button1.Click
'Hash Table speichern
        Dim fs As New IO.FileStream("Test.has", IO.FileMode.OpenOrCreate)
        Dim bf As New _
          System.Runtime.Serialization.Formatters.Binary.BinaryFormatter()
        bf.Serialize(fs, has)
        fs.Close()
    End Sub
 
    Private Sub Button2_Click(ByVal sender As Object, ByVal e As _
      System.EventArgs) Handles Button2.Click
        Dim i As Integer, b As String = ""
'Hash Table laden und wieder anzeigen
        If IO.File.Exists("Test.has") Then
            Dim fs As New IO.FileStream("Test.has", IO.FileMode.Open)
            Dim bf As New _
              System.Runtime.Serialization.Formatters.Binary.BinaryFormatter
            has.Clear()
            has = CType(bf.Deserialize(fs), Hashtable)
            For i = 0 To 10
                b += has(i) & vbCrLf
            Next
            TextBox1.Text = b
        Else
            TextBox1.Text = "Nichts gefunden"
        End If
    End Sub
End Class

Dont debug, because there will allways be one more bug