Windows 10 downloaded a big update not long ago and went through a lengthy upgrade process. Partway through the system locked up. The little progress spinner stopped spinning and it sat there for hours.
So I powered down, the system appeared to go through a recovery process, and then I checked for updates again. It says that "Your device is up to date", but the current version is 1511, build 10586.633. That version isn't current; version 1607 was released in August.
But whenever I check for updates, it says that the system is up to date.
Windows Update troubleshooter reports no problems.
How do I persuade Windows to install 1607?