i am showing you a trick through which you can get any antivirus for free.
first decide that what antivirus you want to use for free and then search like this.
“Antivirus name” + giveaway + 2012 + July;
you need to give current year and current month.
then visit the links and find the poromo page link and then register your self over there and then signup over there and then get the free serial key and active your antivirus.