Public Class Form1

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

    End Sub

    Private Sub Button2_Click_1(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        ListBox1.Items.Clear()
        For Each Archivo As String In My.Computer.FileSystem.GetFiles( _
                                "c:\windows\system32", _
                                FileIO.SearchOption.SearchTopLevelOnly, _
                                "*.dll")

            ListBox1.Items.Add(Archivo)
        Next
        Label1.Text = ListBox1.Items.Count
    End Sub
End Class