as mentioned in my last post above, I uninstalled earlier AIS firewall to give a new shot to CIS 4...couple of hours later I decided to remove CIS and re-add Avast firewall >>> surprise after rebooting: firewall wouldn't start, just a no go. Message in the UI was that the module wasn't running (ie service not even listed in services). Had to go through a full uninstall and reinstall. The thing is there's in fact no "repair" function in the avast installer, it's either change (ie add/remove components, uninstall, or update, and launching the setup file would only prompt to uninstall). So again there was no other choice but a full reinstall.