This evening, Windows 10 invited me to load the next build, as explained here. It is called “windows 10 Home, version 1511, 10586”.
The update started with two downloads and updates (10 minutes), and then a full configuration step (to 100%), then up to three restarts, to copy files, copy drivers and features, and reconfigure the registry. The entire process took about one full hour (HP Envy).
But I had not been aware of what upgrading to a new build means. Kaspersky had to be restarted manually.