[سعود]

كود :

Imports System.IO

Public Class Form1
   Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
       For Each d As DriveInfo In DriveInfo.GetDrives
           If d.IsReady Then
               drv.Items.Add(d.Name)
           End If

       Next
   End Sub
   Dim folders As New List(Of String)
   Private Sub drv_SelectedIndexChanged(sender As Object, e As EventArgs) Handles drv.SelectedIndexChanged
       Dim dr As New DriveInfo(sender.text)
       fld.Items.Clear()
       folders.Clear()
       For Each dir As DirectoryInfo In dr.RootDirectory.GetDirectories
           fld.Items.Add(dir.Name)
           folders.Add(dir.FullName)
       Next
   End Sub

   Private Sub fld_SelectedIndexChanged(sender As Object, e As EventArgs) Handles fld.SelectedIndexChanged
       Dim dir As New DirectoryInfo(folders(sender.selectedindex))
       fl.Items.Clear()
       For Each f As FileInfo In dir.GetFiles
           fl.Items.Add(f.Name)
       Next
   End Sub
End Class