Yeah, so... Basically, as Avast free has no firewall, I need a third-party product (free one as well)... I have tried out Outpost, and that killed my system. Right now, I use COMODO (Firewall only mode), but it's so bloated that everything runs slooooooow. Any other recomendations? Note that primarily I am a Linux user and I'm asking this for my noob parents, so it better be simple too.