Docs ms changing port

From Remote Desktop Wiki

By default, Microsoft Terminal Services accept connections on TCP port 3389.

To modify that port, use a Windows registry editor (such as the built-in regedt32.exe) and edit registry key

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Terminal Server\WinStations\RDP-Tcp

To modify a specific Terminal Server connection

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Terminal Server\WinStations\connection

The PortNumber subkey is the hex value of decimal port.

PortNumber: D3D (3389)

To modifiy a specific connection, substitute the value in the “RDP-Tcp” entry with the port you would like to use. When using the Remote Desktop client, as opposed to entering

127.0.0.1

You would now enter (if you chose port 3399)

127.0.0.1:3399

For more information, see Microsoft Knowledge Base Article Q187623.