win7：
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Terminal Server\Wds\rdpwd\Tds\tcp

win10：
Start the registry editor. (Type regedit in the Search box.)
Navigate to the following registry subkey: HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Terminal Server\WinStations\RDP-Tcp
Find PortNumber
Click Edit > Modify, and then click Decimal.
Type the new port number, and then click OK.
Close the registry editor, and restart your computer.