any free anti virus sucks, think with me, why would them do a really nice free anti virus if all they want is to sell the paid one?
so the free versions mostly, arenot proactive, it just detect if u make some scan and stuff, in others words it detects the virus when it is already in the machine, f@#!ing the system already, the best and paid anti virus, detects and blocks it, b4 it make acess to the system, the reg of windows and others stuff.
so free and virus is almost same thing of nothing.
kaspersky comes with a firewall too which helps even more.
free anti virus is the same of every girl u f@#! without condom, u go make AIDS exame, so what if u got it? u r already f@#!ed lol!