IIS not allowing me to server files with .rdp extension

After a long day of checking, finally realised that they were talking about a different permissions box! In the websites properties removed execute permissions and all is fine now.

The server knows that it should serve the default document when the browser request comes in to the server name or the ip address. It doesn't know that it should serve the default document when the browser request comes in to any other names, whether those names resolve to the ip address or not.

When you specify the URL and the document you're specifically telling the server to retrieve a specific file from whatever web site is running on the ip address that domainname resolves to. It's like retrieving a file from the file system by specifying the absolute path to that file. You could put any file there and retrieve it regardless of whether it's in the documents list or not just by specifying the filename (the absolute path).

You need to add a host header to the web site for domainname so that it knows it should respond to requests for http://domainname.

Of course I could be completely wrong. I don't work with IIS that much.