To expand on the container/vm idea, for someone that’s never done such a thing before, installing whatever OS u want (windows or other) in virtual box then setting the network get internet only from the vpn would be a very secure but not all that hard to do.

The easiest way for a beginner would however be to use a VPN that have its own software with built in kill switch, then you select whatever program you want killed if the vpn goes down, and it just exits that program. (If your paranoid research DNS leaks first)

Can you put together a tldr? I’m glad your writing this but it’s to much for me to take in all at once 😅