The Prevent the computer from joining a homegroup machine setting should be configured correctly. By default, users can add their computer to a homegroup on a home network. If you enable this policy setting, a user on this computer will not be able to add this computer to a homegroup. This setting does not affect other network sharing features. If you disable or do not configure this policy setting, a user can add this computer to a homegroup. However, data on a domain-joined computer is not shared with the homegroup. This policy setting is not configured by default. You must restart the computer for this policy setting to take effect. Fix: (1) GPO: Computer Configuration\Administrative Templates\Windows Components\HomeGroup\Prevent the computer from joining a homegroup (2) KEY: HKLM\Software\Policies\Microsoft\Windows\HomeGroup\DisableHomeGroup