This option is useful if you need to control whether this computer receives unicast responses to its outgoing multicast or broadcast messages. This is an advanced security setting for the Windows Firewall that you can use to allow unicast responses on computers running Windows Vista or later. Fix: (1) GPO: Computer Configuration\Windows Settings\Security Settings\Windows Firewall with Advanced Security\Windows Firewall with Advanced Security\Windows Firewall Properties\Private Profile!Windows Firewall: Private: Allow unicast response (2) REG: HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\WindowsFirewall\PrivateProfile!DisableUnicastResponsesToMulticastBroadcast