Which one is the best free antivirus software?

A security software related question.Many people have opinions like this:the same security software company's antivirus product is good,but the all-in-one security suite(which is based on this same antivirus)is bad.For ex.:nod32vs.

• Answer:

  more and more antivirus companies are now adding full firewall modes into the software packages. Most of them do a fairly good job of protecting the computer from general attacks. The main reason people get worms are via e-mail, new viruses that are not yet detected or via instant messengers, limewire type services. you should also make sure you install the antivirus/firewall on the computer you know is not infected because the antivirus sometimes has a hard time trying to decide if the application is legit or not. I don't like norton or symantec, over bloated and slow. I would consider trendmicro, excellent software via a virus scanner and firewall. They work pretty well together. They also work well behind firewalls as that extra protection, most broad band routers now offer full packet inspection / firewall options. There are many firewall only programs though. "Comodo" is very popular, light version is free, pro is paid but all can be tested for 30 days I think.