I'd really appreciate a way to completely block Windows from the net, and still use FireFox & Chrome.
I've been using Windows7 like this. I manually updated it to a point where it'll run the programs I need, and then permanently disabled Windows updates, firewall, tasks ... etc. I use a 3rd party firewall like Simplewall or Windows10firewallcontrol that clearly tells me when something is trying to access the net, and enable only those MS processes necessary for browsers, Skype, Teams, Minecraft ... etc. When Windows10 is actaully finalized, i.e. no more updates expected and I can use it like an offline box, then I might 'upgrade' to it.