To be honest, as long as they're not on an external network, it doesn't matter what OS they are running as long as it runs the needed software.
There are massive industrial CNC machines running on even older Windows systems than XP because the software won't work on a newer OS. There's no reason to upgrade if it means having to replace a massive multi-million dollar machine.
In Yellowknife, there's a road called "Ragged Ass Road" and that sign gets stolen so often that they started selling the signs in gift shops to reduce the theft rate. Which is super clever ;)
There's a town of Horneytown and Horneytown Rd here in North Carolina. Heard that the country store there does just that, selling shirts and whatnot. I'm guessing the road signs disappear around there frequently too.