I have 2 computers (HUMMER1, HUMMER2) connected to a Gygabyte switch, which is connected to my router. Both computers had "WORKGROUP" as workgroup name. Under Network, HUMMER 1 could see HUMMER 2, the router and a network printer. HUMMER 2 could only see the router. I then changed the workgroup for both pcs to "HOMEGROUP", rebooted, and now the situation has reversed! HUMMER 2 sees the whole network, HUMMER 1 only sees the router. All advice is appreciated. Both PCs running Windows 10 Pro.
Are both machines numbered the same? in other words, do both get their IP addresses from the router using DHCP? And when you say "see each other", how exactly are you looking?
Try this: Go to RUN and type in
that is, the IP address of the other machine, and hit Enter.
If the other machine it is sharing a folder then you should be able to see it.