Imports System.Windows.Forms
Imports System.IO
Imports System.Collections.Generic
 
    Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) _
      Handles MyBase.Load
        TreeView1.Nodes.Add(GetDirectoryNodes(New DirectoryInfo("C:\")))
    End Sub
 
    Public Function GetDirectoryNodes(dir As DirectoryInfo) As TreeNode
        Dim node As TreeNode = New TreeNode(dir.Name)
        'Nachsehen, ob für diesen Knoten Unterknoten (Unterverzeichnisse) 
        ' vorhanden sind
        Try
            Dim subdirs As IEnumerable(Of DirectoryInfo) = _
              dir.EnumerateDirectories()
            For Each subdir As DirectoryInfo In subdirs
                node.Nodes.Add(GetDirectoryNodes(subdir))
            Next
        Catch ex As Exception
            'Fehler beim Zufriff; ignorieren
        End Try
        Return node
    End Function