Why are those wretched computer menaces called "viruses"? It's actually a pretty good analogy: Like the kind that infect humans, the pieces of code that attack your computer are parasitic, relying on the "host" (in this case, your machine) to provide a life environment; they spread from host to host, occasionally mutating as they go; and some of them are much more debilitating than others, even though the most debilitating tend to drive themselves to extinction through their sheer toxicity. (A virus that kills computers before they can pass along the infection is not a virus that propagates itself effectively.)
Biologists have no cure for virus-borne ailments, but the computer realm's a bit better off: A good antivirus package can smite the critters before they have a chance to attack. Steve notes that though most computers these days ship with some sort of antivirus software installed, there are two problems.
First, no antivirus program is totally up-to-date; whatever you use, you'll have to make sure it freshens its virus definitions (the info that tells it how to recognize new viruses) every blessed day. Second, though the software on that new computer is fully functional (albeit in need of refreshment), your subscription to it--the thing that allows you to get those definitions--doesn't last forever. If you don't pay to subscribe to the program before it expires, the definitions rapidly become out-of-date, and therefore worthless.
So, if you've got to spend actual money on this stuff, which one should you get? Steve uses Norton AntiVirus, though he's not wild about Symantec's fees: $30 per incident for phone support, and an upgrade system so dysfunctional you're often better off simply buying an entirely new version of the program. He also likes Trend Micro PC-cillin, which is not only a favorite with the PC World testing crew but comes with free phone support.
He doesn't like the widely used McAfee VirusScan, which Angela uses (though not, if one is to judge by her reaction to Steve's comments, with great enthusiasm). The important thing, she says, is to be sure that whichever program you choose is scrupulously updated, even if that means laying out cash on a regular basis. And, she counsels, users should occasionally step aside for a few hours and let their program of choice make a thorough scan of their system, looking for the most insidious bad guys.