if you have problems in the future (with the new installation), maybe you should make a clean un-/reinstall of the firewall.
i never was directed to a comodo site to get an update. but this may be related to a change in version, as i think you had version 3 before.
when there is nothing about antivirus on the main page of the userinterface, you dont use the antivirus part of comodo.
(you could decide to) disable the sandbox of comodo, because you want only the firewall. but i would suggest to use the defense+ together with the wall.