See my answer in this post.
Run those Powershell statements to enable network discovery.
If you use a local account to log on to the desktop, the account name and it's password need to be identical on all machine to allow it to authenticate.
My to Dell computers are not connecting on the network. One computer does not show the name of the other computer in the Network window. One shows both but I get this message when I click on the computer icon name You do not have permission to access \computer name-pc