Old Homegroup won't go away

Teredo Tunnel is part of the problem. See if the following helps you out in any way. This is about the best I could find. You are welcome to search further if the below does not work out.

Fix issues with the homegroup in Windows 10
Solution 1 – Delete files from PeerNetworking folder
Go to c:\windows\serviceProfiles\LocalService\AppData\Roaming\PeerNetworking.
Delete idstore.sst and move on to Step 3. If deleting idstore.sst doesn’t work, go back to c:\windows\serviceProfiles\LocalService\AppData\Roaming\PeerNetworking and delete all files and folders in it and go back to Step 3.
Go to the Network Settings and Leave the Homegroup.
Repeat this for all the computers in your network.
Turn off your computers.
Turn on just one, and create a new Homegroup on it.
This Homegroup should be recognized on all of your computers now.
Solution 2 – Enable Peer network grouping services
Sometimes it can happen that services needed for Homegroup to work are disabled for some reason, but there’s a way to enable them.


In the Search bar type services.msc and search the list for peer network grouping, peer network identity manager, homegroup listener and homegroup provider.

If those services are disabled or set to manual set them to auto and leave your Homegroup.
Create new Homegroup and see if it works.
We have to mention that you might have to do this for all the computers in your network.


Solution 3 – Allow Full Control to MachineKeys and PeerNetworking folders
Find:
C:\Program Data\Microsoft\Crypto\RSA\MachineKeys
And then find:
C:\Windows\ServiceProfiles\LocalService\AppData\Roaming\PeerNetworking
Right click each folder and choose Properties.
Go to Security tab.
You’ll see group of users, click on a group, and press Edit.
From the list of options, click Full Control.
Repeat the process for all that you wish to have access to your Homegroup.
We have to mention that you might have to do this for all of your computers in a network.