Private Sub TreeView1_AfterSelect(ByVal sender As System.Object, ByVal e As _
  System.Windows.Forms.TreeViewEventArgs) Handles TreeView1.AfterSelect
        TreeView1.Nodes(0).ExpandAll() 
 
        With e.Node
 
            If .Name = "Knoten1" Then
 
                Dim myMDIStammdaten As New MDIStammdaten
                MDIStammdaten.Show()
                Me.Hide()
            End If
 
        End With
    End Sub

Private Sub MDIStammdaten_Load(ByVal sender As System.Object, ByVal e As _
  System.EventArgs) Handles MyBase.Load
 
        Me.Focus()
 
    End Sub