enter "\PCNAME" and it should give you access.
Sure it will - if you have a user account on that computer or know the password of that computer's user.
Homegroup was temperamental but most of the time it worked on a LAN. Microsoft's change has made things far more complex and is particularly difficult if your connection to Internet is flakey.
Microsoft refers to 'Specific people' but fails to define who they are and how these people can be determined.