It's downloading the ISO.
See step 4 part E) here: Windows 10 - Upgrade Installation - Windows 10 Forums

The title of the thread: Where can i download - Upgrade to Windows 10 Pro, version 1511 update?
The latest ISO's are after that,so it is what he needs. winver says version 1511.
10586 is good,...

That should be good. The build is 10586 version is 1511 ´read winver very carefully.

Let me explain, a build upgrade(as opposed to a version upgrade) is basically the same, as a repair install.

The MCT will have the latest build.

Also read this tutorial, it has a link to the MCT(Media Creation Tool) too: Windows 10 - Upgrade Installation - Windows 10 Forums

Windows 10