When something works I don’t like changing it. My main observatory computer is running Win 7 (and CCDSoft and TheSky 6!) but I have one old machine that is still running legacy software on an XP box. All of these machines are firewalled off from the Internet (both inbound and outbound) by my router and even the Win 7 machine no longer auto-updates since MS updates have a horrible habit of breaking things (they broke remote desktop a few months ago on one of the Win 7 machines I do allow to update). I can remote onto the observatory from outside my home network using a VPN. In the vast majority of cases of these “embedded” applications there is no need for internet access. Updates you want, such as orbital elements etc. can be done manually under your control. Even Win 10 doesn’t reboot randomly if it is firewalled off from the MS mother ship.