The instructions below can be used to connect to an Ubuntu instance on Google Cloud using the RDP protocol on Windows (pro):
1. sudo apt update
2. sudo apt install tasksel
3. sudo tasksel install ubuntu-desktop
4. sudo systemctl set-default graphical.target
5. sudo passwd root // set root password, if you don't remember it
6. sudo apt install xrdp
7. sudo systemctl enable xrdp // This will start RDP service
Open Windows' Remote Desktop Connection now, enter your IP address and click Connect. To log in, use "root" as both the username and password.