I haven't had any problems personally, but I have had numerous problems with clients. The most recent one was a mortgage broker where a windows update just plain broke the connection between the workstations and the database on the server. It's a paradox database, I think, and It's really the vendors fault for not keeping up, but still a PIA. Took us a while to figure it out.
BTW, this isn't just a Microsoft problem. I have a client using Rapid Recovery backups (used to be Dell AppAssure). This is a high-dollar system that mostly works really well but every other month a firefox update or a chrome update breaks the ability to load the web interface of the thing. It's never-ending. You have to use one of these two browsers, but which one actually works changes all the time.