I created a Windows 8.1 VM on Azure and installed VS 2013 Premium with update 2 on it. Then I tried to register my Lumia 1020 (WP 8.1 installed) using "Windows Phone Developer Registration 8.1" but it says "Unable to connect to a phone. Make sure that the Windows Phone IP over USB Transport (IpOverUsbSvc) service is running.
So... I checked, the service is running indeed, but the Lumia phone on the VM's File Explorer shows up as a "MTP Device". I wonder what's wrong? But my local machine recognizes the phone.