Download? What, from the client side?
<a href="myDocument.pdf">Download the document</a>
If you need to download anything on server side via HTTP or FTP using .NET code, you can use
System.Net.HttpWebRequest
or
System.Net.FtpWebRequest
.
See, for example, my past solutions:
FTP: Download Files[
^],
how to download a file from internet[
^].
—SA