Viruses and worms are running rampant. Last week I discussed the latest threats; this week I'll tell you how I protect myself from worms and viruses.

I've had lots of viruses and Trojan horses arrive on my PC in attachments, and I've even inadvertently downloaded a few. But I've never had a virus infect my system. And only once, when I got really careless, did I have a worm residing in the background (only for about five minutes).

I rely on a combination of prevention, caution, and paranoia.

Prevention

I update my antivirus signature file daily, and it's set to run 7:00 a.m. so I start my day feeling protected. If there's been a rash of virus and Trojan horse stings, I'll hit the upgrade button again midday and even later in the evening. My buddy and computer consultant Rod Ream's advice is "it's wise to manually check for antivirus updates before reading your e-mail, particularly if your system has been powered off, or at a time when a new virus is being reported." It's the "safe not sorry" routine I follow.

Any antivirus program will do. Many people use Network Associates' McAfee or Symantec's Norton products, but I prefer the smaller outfits with strange-sounding names, such as Kaspersky. You may be curious about the antivirus program I use. It's Grisoft AVG Anti-Virus and it's worked fine for me for the last few years. (The fact that it's free doesn't hurt either.) I learned about AVG from PC World Contributing Editor Scott Spanbauer when I asked what he liked. If you want to explore antivirus software, you can read Scott's "Free Antivirus: Finally Ready for Prime Time," then play around with his recommendations.

If you do want to use another antivirus program for a while, make sure you disable the one you're currently using. And because I know about your voracious appetite for things to try, I think you'll want to check out a couple of software collections from our Downloads site: "Free Antivirus Tools" and "Top Antivirus Tools: Add a Layer of Protection To Norton, McAfee."

BTW, many of the programs Scott mentions let you update the signature files without a costly upgrade. That's something I like. OTOH, you might be interested in reading about Network Associates' strategy to keep you hooked on its McAfee antivirus program. The story is "Sneakwrap Files: McAfee Automatic Renewals" and it's from InfoWorld, a fellow IDG publication.

Dig This: If you haven't heard about Microsoft suing 17-year-old Mike Rowe, it's something you need to know about. It has to do with Mike's domain name. I know some of you are just dying to hear the outcome of poor Mike's situation. Turns out Mike agreed to change his domain name; in return Microsoft is giving him a new Xbox and other goodies. (Oh stop being so cynical; he's just 17, remember?) [With thanks to Kim Saccio-Kent.]

Caution

What makes protecting yourself more difficult--and the thing that drives me nuts--is Microsoft's attitude about file extensions. Microsoft developers insist on hiding file extensions by default. They somehow think your Windows experience will be more pleasurable because you don't have to bothered with the file's real extension. That's dumb: Unless you see the entire file name, you wouldn't know that it could be dangerous and might be tempted into clicking it. Take a few minutes and read through "For Security Reasons, It Pays to Know Your File Extensions," from Scott Dunn's Windows Tips column.

With file attachments such a tremendous risk, I rarely click on them. In fact, as an extra measure of safety, I have Zone Alarm Pro's File Attachment enabled so every dangerous file is automatically renamed. That way I can't easily execute any of them and get myself in trouble.

If you're an experienced, careful user, and with Scott's article under your belt, I feel pretty confident in saying that you won't be infected when clicking on a limited number of--and very specific--files attached to e-mail. Most images are safe (.jpg and .bmp, for instance), as are video files (say, .avi, .mpg, and .wmv).

Dig This: You heard about the Mars landing, I know; but what you didn't see was this censored photo. [With thanks to Carl Siechert.] [Small image]

Paranoia

I run a few programs every week to keep my system squeaky clean: Spybot, Ad-aware (Why both? I really, really don't want spyware on my PC.), and TrendMicro's Housecalls, a great online virus checker.

Sign up to have Steve Bass's Home Office Newsletter e-mailed to you each week.