how to create a dynamic tree view to display all the drivers from my computer in asp.net

TreeNode diskc = new TreeNode("C:\\", "C:\\");
           diskc.PopulateOnDemand = true;
           TreeView1.Nodes.Add(diskc);
           TreeNode diskd = new TreeNode("D:\\", "D:\\");
           diskd.PopulateOnDemand = true;
           TreeView1.Nodes.Add(diskd);
           TreeNode diske = new TreeNode("E:\\", "E:\\");
           diske.PopulateOnDemand = true;
           TreeView1.Nodes.Add(diske);

protected void Page_Load(object sender, EventArgs e)
   { if (!IsPostBack)
       {
           TreeNode diskc = new TreeNode("C:\\", "C:\\");
           diskc.PopulateOnDemand = true;
           TreeView1.Nodes.Add(diskc);
           TreeNode diskd = new TreeNode("D:\\", "D:\\");
           diskd.PopulateOnDemand = true;
           TreeView1.Nodes.Add(diskd);
           TreeNode diske = new TreeNode("E:\\", "E:\\");
           diske.PopulateOnDemand = true;
           TreeView1.Nodes.Add(diske);

           TreeView1.CollapseAll();
       }

       TreeView1.TreeNodeExpanded += new TreeNodeEventHandler(TreeView1_TreeNodeExpanded);
       TreeView1.SelectedNodeChanged += new EventHandler(TreeView1_SelectedNodeChanged);

   } void TreeView1_SelectedNodeChanged(object sender, EventArgs e)
   {
       ModalPopupExtenderMessage.Show();
       _browseTextBox.Text = TreeView1.SelectedValue;
   }

   void TreeView1_TreeNodeCollapsed(object sender, TreeNodeEventArgs e)
   {
       ModalPopupExtenderMessage.Show();
       //throw new Exception("The method or operation is not implemented.");
   }

   void TreeView1_TreeNodeExpanded(object sender, TreeNodeEventArgs e)
   {
       if (e.Node.Value.EndsWith("\\"))
       {
           AddNodes(e.Node.Value, e.Node);
       }
       ModalPopupExtenderMessage.Show();

   }
   private TreeNode AddNodes(string path, TreeNode parentNode)
   {
       FileList objList = new FileList(path, "*.*");
       TreeNode node = new TreeNode(path, path);
       for (int index = 0; index < objList.Directories.Length; index++)
       {
           string directory = objList.Directories[index];
           TreeNode objChildNode = new TreeNode(directory, path + "\\" + directory + "\\");
           objChildNode.PopulateOnDemand = true;
           objChildNode.Target = "_blank";

           parentNode.ChildNodes.Add(objChildNode);
       }
       foreach (string file in objList.Files)
       {
           TreeNode objChildNode = new TreeNode(file, path + "\\" + file);
           parentNode.ChildNodes.Add(objChildNode);
       }
       ModalPopupExtenderMessage.Show();

       return node;

   }


   protected void _browseButton_Click(object sender, ImageClickEventArgs e)
   {
           string path = _browseTextBox.Text.ToUpper();
           if (path != "")
           {
                   TreeNode > 0)
           {
               return System.IO.File.Exists(_browseTextBox.Text);
           }
       }
       ModalPopupExtenderMessage.Show();

       return true;
   }