Upload a file to a web server from winforms app

Background Intelligent Transfer Service (BITS)

https://msdn.microsoft.com/en-us/library/aa362708(v=vs.85).aspx

Most web servers don't allow you to upload files directly to the server. Unless the server has specifically been configured to enable WebDAV, you either have to transfer the files using FTP, or send them to a specific handler on the server.

You'll need to know how the server will be handling your uploads before you can start.