The free anti-virus software isn't updated as much and doesn't protect your computer as well as what is generally believed. Programs like NOD32 go above and beyond what is required to keep your computer safe. With a program like NOD32 you are only going to get screwed by a virus if you want to get screwed by one. The people who make it are constantly updating it, almost daily because that is what is required. There are new viruses created everyday, so the yearly price is required to keep up with the huge demand.