Windows 10 and too many connections ...

This weekend, I decided (foolishly...) to upgrade the only Windows 10 box that we have, a NUC that me and Peter use for some gaming time. This ended up being an enormous mistake (read: clusterfuck), because the box sort of bricked itself with an error

The number of connections to this computer is limited and all connections are in use right now.
Try connecting later or contact your system administrator.

So, neither of the proposed solutions worked; I even tried rebooting numerous times, to try to get it to Safe Boot, which it did not. And lo and behold, Windows 10 has removed the F8  boot option to go into safe mode as well... I did a little bit of research on this, and found a solution that suggested disconnecting the box from the LAN. Well, this was easily said than done, since the box is on WiFi, and you can't turn off WiFi from Windows unless you can boot into it. But, there is a BIOS, and fortunately, this Intel NUC machines has a BIOS option to turn off the WiFi (what they call the WLAN).

I did that, and this time Windows continued booting, finished with the upgrades that I had started, and so far so good. I haven't turned on the WiFi yet, so we'll see what happens after I do that...