Old unknown credentials blocking networking

Eagle51 said:

The Workgroup is already created by windows. You just need to make sure you have Network Discovery and File & Print Sharing turned on for the computer your wanting to create the share on, then share the folder and set the share permissions.

Turn On or Off Network Discovery in Windows 10 Windows 10 Network Sharing Tutorials

How to set up file sharing on Windows 10 | Geek Squad

This worked with two of the computers, but the third one can't join the HomeGroup. We tried here:
ControlPanel > Network & Internet > HomeGroup

We gave permission to share files and printers.

This appears when trying to join: "This computer can't connect to a HomeGroup."

Any suggestions to get over this? Is it possible that any setting in WorkGroup is creating the problem? We first tried to set up a WorkGroup before realizing that isn't what we need.

Thanks.

This worked with two of the computers, but the third one can't join the HomeGroup. We tried here:
ControlPanel > Network & Internet > HomeGroup

Have you tried the HomeGroup Troubleshooter ?

Eagle51 said:

Have you tried the HomeGroup Troubleshooter ?

Yes. It doesn't find anything (recommends to troubleshoot the network, when we do this, nothing is found).

HomeGroup and Network Troubleshooter should have checked and fixed any services that might not have been running, but lets double check them and make sure :)
WinKey + s, type services, select services from the list.
Find the following and make sure they are running ... if any are not running, then right click on it and click Start.
HomeGroup Listener
HomeGroup Provider
Peer Networking Grouping
Peer Networking Identity Manager

Eagle51 said:

HomeGroup and Network Troubleshooter should have checked and fixed any services that might not have been running, but lets double check them and make sure :)
WinKey + s, type services, select services from the list.
Find the following and make sure they are running ... if any are not running, then right click on it and click Start.
HomeGroup Listener
HomeGroup Provider
Peer Networking Grouping
Peer Networking Identity Manager

All were off. It was possible to turn on/start the two Peer Networking options. The two HomeGroup options are set to manual and cannot be modified; we get a message saying Windows cannot start them. Any idea why or how to fix this?

Thanks.

Ok ... Check Services again and make sure the following are running. If not, start them, then try to start the 2 HomeGroup Services.
Peer Name Resolution Protocol - Startup Type should be Manual
Security Accounts Manager - Startup Type should be Automatic
Windows Firewall - Startup Type should be Automatic

Note: I think the default Startup Type is Manual for the following. Not sure if your gonna have to change any to Automatic, lets wait and see if we can get them running first :)
HomeGroup Listener
HomeGroup Provider
Peer Networking Grouping
Peer Networking Identity Manager

The HomeGroup Listener and HomeGroup Provider are still problematic. More specifically, in Services:

Peer Name Resolution Protocol - Startup Type should be Manual = "Running Manual"
Security Accounts Manager - Startup Type should be Automatic = "Running Automatic"
Windows Firewall - Startup Type should be Automatic = "Running Automatic"

HomeGroup Listener = "Manual", not running
HomeGroup Provider = "Manual (trigger start)", not running
Peer Networking Grouping = "Manual" and running
Peer Networking Identity Manager = "Manual" and running

Darn!

There's one last thing I can think of to check and that's to make sure IPV6 is enable.
Open Command Prompt as Admin
ipconfig /all

copy and paste the result.

Eagle51 said:

There's one last thing I can think of to check and that's to make sure IPV6 is enable.
Open Command Prompt as Admin
ipconfig /all

copy and paste the result.

Made a snip as the list is long. We saw IPV4 but not IPV6.

Looks good to me ....
Sorry ... I couldn't help you, hopefully someone with more Home Group knowledge can help you.

You might want to check your system, if you haven't done so lately.
Reboot PC ... then run the following commands
Open Command Prompt as Admin
sfc /scannow
Dism /Online /Cleanup-Image /RestoreHealth

Note: They can take awhile to run, so be patient :)