Hello,
Yes, NoMachine can be ran on EC2. The public IP is not displayed in NoMachine GUI because the UPnP, which is used by us to obtain such addresses, is not compatible with the network infrastructure that Amazon has in their server rooms. It should work on your home or office setup. Nevertheless, to connect to the NoMachine on EC2 you need to use a public IP that is displayed in your Amazon console when you click on your Windows instance and see the “Description” tab. One of the fields reads ‘Public IP’. Please use the address stored there. Additionally you must make sure that port 4000 is allowed for traffic in your security group (same as you did with SSH). After doing so you should be set for using NoMachine to connect to your EC2 Windows.