This was a bizarre problem that cost me half a day. I was unable to share folders from my Windows 10 PC, and I was near despair when I found the solution.

I tried searching Google for many different phrases before I found the answer. This was the basic symptom: My shared folders were not accessible to other machines on the network. However, when I tried to connect to them from the same machine, it worked fine. Well, except it didn’t. Let me explain.

My machine is named “David-W10”. It has Hyper-V running, so I have a couple of extra virtual network cards with private IP addresses in the 172.20.x.x address space. I have both IPv4 and IPv6 active.

  • If I tried to browse to \\David-W10 from other machines on the net, no luck.
  • If I tried to browse to \\David-W10 from the David-W10 machine itself, it worked fine. It turns out this is because the name resolution was returning my IPv6 address.
  • If I tried to browse my IPv4 address \\192.168.0.22, it did not work.
  • If I browsed to my Hyper-V adapter \\172.22.80.1, it worked fine.

I disabled all the firewalls. No change. I searched and dug, and finally found this article: https://superuser.com/a/1296023

As the author states: “Here’s the solution I discovered. (You might want to grab a beer first…)”

I was missing many registry keys. Why? No freaking idea. I’m on Windows 1803 with Hyper-V and Docker running. This is a fairly new clean install. I don’t much about in the registry or do weird stuff. I followed those directions, added the keys, rebooted, and magic! It all works now. Grr.