Imports System.IO
 
Public Class Form1
 
    Private Sub searchFiles(ByVal path As String, ByVal mask As String)
        Application.DoEvents()
        Try
            Dim dir As New DirectoryInfo(path)
            For Each File As FileInfo In dir.GetFiles(mask)
                lstSuchen.Items.Add(File.FullName)
            Next File
            For Each di As DirectoryInfo In dir.GetDirectories()
                searchFiles(di.FullName, mask)
            Next di
        Catch ex As System.Exception
            MessageBox.Show(ex.Message)
        End Try
    End Sub
 
    Private Sub btnSuchen_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles btnSuchen.Click
        If FolderBrowserDialog1.ShowDialog() = _
        System.Windows.Forms.DialogResult.OK Then
            lstSuchen.Items.Clear()
            searchFiles(FolderBrowserDialog1.SelectedPath, txtSuchen.Text)
            MessageBox.Show("Fertig!")
        End If
    End Sub
End Class