A reader passed along this visual reminder about the risks of using consumer operating systems on digital signage jobs.
This is a big video wall in one of the walkways connecting the World Trade Center are in New York with transport hubs. The error message has to do with hard disk storage.
It has been a long time since I ran ops for a network, but I am pretty sure there are ways to disable these sorts of error messages from popping up, and also ways to minimize the risks of big ad screens turning into broken PC desktops.
You certainly see this sort of thing now and then in small business environments, but this is a high profile, heavy foot traffic space.