Microsoft stated that Windows 10 would be the last version, becoming a “service” rather than a product. However, it seems like that’s no longer the case.

Create your own account as administrator and make non-admin accounts for your sons to limit privileges of software they install. Some games may require admin rights (anti-cheat mostly), so you might prefer to provide them an administrator account and try to educate them on privacy and malware and how to only install trusted software but that is for you to decide based on their maturity.

Make sure they only obtain games from trusted stores such as steam, itch.io, gog, epic. I’m not philosophically against piracy but software piracy is very risky.

Another thing is to teach them to not install hacks and cheats even if you think they wouldn’t do it in a million years. As a LAN organiser I have known several good kids that have experimented with hacks, I don’t believe this is a significant moral failing for a child but it is extremely risky software for security and a good way to get banned from the local gaming scene.

General security and privacy practices apply as always, use anti-virus on Windows, use a password manager, use 2FA, never share passwords, principle of minimum privilege ie use non-admin as much as possible.

Use floss and privacy respecting sevices as much as possible… but kids are going to play the games their friends play and discord is hard to avoid.

If their social circle is not already embedded in discord then consider self hosting a VoIP server for them.