My antivirus program is good and runs an automatic full scan (it takes over 3 hours) once a week and a quick scan every single day. And of course, I have a firewall too so I feel confident in my protection against any virus, although I'm still envious of the people with MAC's. It is not fair how they don't have to deal with viruses.
And to Karlos. You say you don't have a good antivrius program. Therefore, you should download the best free virus software out there which in my opinion is AVG.
www.free.avg.com