Windows feature updates might fix the desktop not appearing

I recently worked with a Windows 10 computer that, on only one user account, had stopped displaying the desktop and task bar (all Explorer components). Explorer tried to start, but pegged one CPU core and never got around to displaying anything. The Windows Push Notifications User service for the stuck account displayed similar behavior. I found a handful of purported fixes on the Internet for the lack of desktop, but none of them helped. What did help was the 1803 feature update that happened to be coming down - after the system installed it and rebooted, everything was functioning normally.