Some time new windows installation finished with out many firewall role including remote access by server manager :
To set the windows firewall rule in order to allow remote connection, just run :
netsh advfirewall firewall add rule name="Windows Remote Management (HTTP-In)" dir=in action=allow service=any enable=yes profile=any localport=5985 protocol=tcp
After that you will be able to add this server to Server Manager and control it
Good Luck