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.
another Solution:
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.
And another:
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.