- Open Windows Settings under Start Menu or press Windows key + I for an instant access.
- open Update & Security.
- Open Troubleshoot from the left pane.
- click on Run the troubleshooter.
- wait until the troubleshooter scans and hopefully resolve issues.
If the above doesn't work then
Delete the files from PeerNetworking folder:
- Under PeerNetworking folder, delete all files. You can try deleting only the idstore.sst file, but the total wipeout is the better choice.
- go to the Network Settings and leave the pre-created homegroup with all PCs.
- Restart your PCs (all within the group) and disable the connection for all but one.
- Use that one PC to create a new group and save the generated password.
- Connect the remaining PCs, insert the password and it should now work.