Thank you for your replies. I'm a little bit confused (nothing unusual there!) but hopefully it becomes a bit clearer soon.

Is there an OEM vs Retail situation with this, do you know?

Thanks.

I'm possibly interested in buying a license for Windows Server 2012/16 Standard Edition. How can I do that?

I've searched around on the net. The Microsoft Store is out of stock of the only version...

Ok, so finally:

I completely reinstalled Windows again (!), but this time without allowing any internet access.

I then manually installed the update from the CAB file. And that worked.

But...

Hi. I've been trying to install update KB3194496, but without success.

Before installing it, DISM /CheckHealth reports "No component store corruption detected.".

When trying to install the...