I struggled with this for two days and finally found a solution. I have 3 computers on a network; 2 running Windows 7, 1 running Windows 10. This solution assumes you're ok using password protected sharing.
On the Windows 7 systems:
- Leave the HomeGroup (Control Panel > Network and Internet > Network and Sharing Center > HomeGroup > Leave HomeGroup)
- Set the network location to Work network, not Home or Public (Control Panel > Network and Internet > Network and Sharing Center > Under View your active network, make sure this option says "Work network")
- Don't allow Windows to manage homegroup connections (Control Panel > Network and Internet > Network and Sharing Center > Change advanced sharing settings > Under the Home or Work (current profile) option, set the HomeGroup connections option to Use user accounts and passwords to connect to other computers
Once I changed the setting in step 3 above, Boom!, all computers could be seen and accessed from every other computer. Good luck everyone. Networking with Windows systems could be greatly simplified.