You aren't supposed to disable your firewall, but give it an exception in what ever it is.
if he disables it and the game works properly, then we can worry about adding exceptions.
if the program still doesn't work, it isn't the firewall and we don't have to worry about it. disabling a firewall is usually just a checkbox on/off, adding an exception is... what, 3 menus, typing, finding a file... screw that, let's not if we don't have too, eh?