Not my story to tell, so I'm relaying it. Childhood friend works for a big company, you've heard their name, they make nuclear control systems for nuclear reactors; they have products out in the field they support and there are new reactors in parts of the world from time to time. We were scheduled to have lunch a couple years back and he bailed, we rescheduled, he bailed because that was the day you couldn't defer XP updates anymore, they came in and some XP systems became Windows 10. XP was "nuclear reactor approved" by someone, they had a tool chain that didn't work right on other versions of windows, it all gave me chills.
They ended up giving MS a substantial amount of money to extend support for their use case for some number of years. I can't remember the number he told me but it was extremely large.
It sounds like he said XP machines auto-updated to Windows 10, and they would have had to have been connected to the internet in order to download that update. (I'm assuming, optimistically, that these were more remote-control computers than actual nuclear devices.)
They ended up giving MS a substantial amount of money to extend support for their use case for some number of years. I can't remember the number he told me but it was extremely large.