You want to look up FileSystemWatcher to react to changes.
If you aren't familiar with the System.IO namespace for iterating
folders and files, check here:
http://www.eggheadcafe.com/tutorials/aspnet/cea7ec01-3944-4295-8512-462b2a15a09b
/net-read-and-write-files.aspx

Signature
Robbe Morris - 2004-2006 Microsoft MVP C#
I've mapped the database to .NET class properties and methods to
implement an multi-layered object oriented environment for your
data access layer. Thus, you should rarely ever have to type the words
SqlCommand, SqlDataAdapter, or SqlConnection again.
http://www.eggheadcafe.com/articles/adonet_source_code_generator.asp
>I would like to know the best way to load a Treeview in VB.NET 2005 with
>the
> directories and files located in a path on the hard drive. I would also
> like
> to know the best way to refresh this view when a file was added or deleted
> from the file system as well.