Keep reading in this section of the forum, and see if anything for earlier versions of Windows can be used as clues to how to do it for Win 10. BUT...it is almost 20 years old! Might be time to finally upgrade!
I have gotten some really, really old programs to run by setting up a Windows Virtual Machine, and running inside that - but cannot advise on the availability of that process with Win 10. Do a search on the term to come up with both pay and free possibilities to try. In all cases, you'll need a copy of the original system disk (Win98, XP, etc.) that you want to try to run RF G2 on.
Back in the day there was a download "GreatPlanesInstallationFix". I still have it on a disc . I used that to get G2 to install . However , that's just the start of the problems Lol . The main problem is that G2 used Safedisc 2 protection which is no longer supported by Windows , apparently due to security issues . So Windows doesn't recognise that the disc is genuine and doesn't run the program . I have managed to get around it but it's a lot of agro , then I can't map the controls to my current interlink , so throttle ends up on the rotary knob .