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Common wisdom is that you do, but the answer might surprise you.

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This is Leo Notenboom for

Every so often I get asked by someone if they really need anti-virus software.

Common wisdom is that you do, and true to that label it's a wise thing to do. In fact, if you have any doubt what the answer to the question is, then the answer for you is clearly, positively yes. Yes you do need to run anti-virus software, and of course keep it up to date.

But you can tell from the way I put that, I left us an out.

Here's the deal - anti-virus software monitors and scans for and (hopefully) eradicates any viruses that appear on your machine.

Well, what if they never appear? Or if they do appear, what if they never get executed?

Well, then it follows that your anti-virus software is kinda redundant. Perhaps even pointless.

So there you go: if you can be 100% certain that you're able to prevent viruses from even reaching your machine or you're 100% certain that a virus would never get executed, then you're done. You don't need anti-virus software.

"I run anti-virus software and I have for years."

Remember: you need to be 100% certain.

Now, it may sound like I'm being a little sarcastic or facetious, and I suppose I am a little. But on the other hand, I do know people who match that criteria. A good friend of mine runs without anti-virus software. He's not a geek, but he is very internet savvy. He can get away with it because he knows what he's doing.

Personally, I run anti-virus software and I have for years. But to be totally honest, I probably haven't had to. I've never been infected and the anti-virus software has never detected an actual threat. Like my friend, I too kind of know what I'm doing and how to avoid viruses in the first place.

But I have come close a time or two. I almost fell for a phishing scam some months ago. Had I done so, it could have resulted in a real infection.

So I'll keep running anti-virus software. In my opinion it's cheap insurance even for those who know what they're doing, or especially those who just think they do.

As for everyone else? It's a requirement. Run anti-virus software and make sure to keep it's database of threats up to date.

Oh, and get behind a firewall. Everyone needs that - know-it-alls and newbies alike. That's actually a key part of keeping the viruses at bay in the first place.

I'd love to hear what you think. Visit and enter 11905 in the go to article number box to access the show notes, the transcript and to leave me a comment. While you're there, browse over 1,200 technical questions and answers on the site.

Till next time, I'm Leo Notenboom, for

Article C3179 - October 13, 2007 « »

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Leo Leo A. Notenboom has been playing with computers since he was required to take a programming class in 1976. An 18 year career as a programmer at Microsoft soon followed. After "retiring" in 2001, Leo started Ask Leo! in 2003 as a place for answers to common computer and technical questions. More about Leo.

Not what you needed?

October 14, 2007 2:48 PM

This might have only a slight relation to the title but read this bit and then delete if u must :( -------->I have sent you a e-mail at [removed] if you could reply to that, that would be great,in relation to this does port forwarding open up a route past ur firewall and anti-virus and how do you do it.I have done everything I have a ip address ive set up the ports UDP and TCP or whatever they are cant remember for a netopia 2247 to use on utorrent but it wont work im runnig windows xp pro sp 2.

October 19, 2007 1:53 PM

I agree 100% Leo. I am one of those that knows and my AV has not had to work for over 2 years. I keep it around as it is not intrusive and requires minimal attention (unlike some AV's starting with an "N".)

A good Firewall is essential. A bad one is better than standing in the middle of the road, but get a good one (research, research, research).

Thanks for all the pearls Leo. Makes us know-it's feel we are not as stupid as the commoners think.

jose A. silva
October 20, 2007 6:40 AM

Hi, by any chance do you have any info in spanish.i would like to know.thank for all the info you give us .

Att: jose.

Doug Woodall
October 20, 2007 6:52 AM

Unless you're really good with computer security, you need AntiVirus, AntiSpyware, and a reliable Firewall. The casual user will not be able to stop their system from becoming vulnerable.

October 20, 2007 7:41 PM

I have an old cheap underpowered laptop in the kitchen on a wireless connection. I look at the weather and read the news on from Washington Post, yahoo, MSNBC and the like in the early morning. I put AV on it and it was so slow and it took 5-10 minutes to boot up. My coffee was made before it booted up. I took off the AV and it runs fine. It has been a year now and I haven't had any problems, but I don't visit any odd web sites.

October 22, 2007 12:04 PM

How do you rate free antivirus? I was advised by a geek to stop Norton and use AVG (

October 23, 2007 4:58 AM

I was advised by one of my brother-in-laws that works on computers daily. He told me that "N" and "M" do not check there own execution files when searching for virus's. He pointed me towards AVAST anti-virus. Have never had a problem with it and it has caught virus trying to sneak in a couple of times now. I won't run without AV or spybot. Even though I have been around awhile, there is always the chance that I will stumble into something that would be bad. Thanks for all the advice you give out, I find it very informative.

October 26, 2007 8:41 PM

Dear Leo, just like you, I have never lost a single bit because of viruses for 20 years, but I do always have an anti-virus software running.

However, I think I am not that agreeable that we can be safe without anti-virus software. This may be true in the olden days where nothing get executed without you explicitly do so. Nowadays worms can get into our system (especially for Ms. Windows) and get executed. Even we ensure our systems are properly patched and firewall running, the risk is still there.

john cowton
October 30, 2007 5:16 AM

i have always used 1 anti-virus and 1 firewall ( apart from windows)afterall when you leave home you lock your doors dont you.

Ivan Tadej
October 31, 2007 9:54 AM

Yeah Leo, I totally agree with you on this one. In my opinion, the anti-virus program is not at all such a necessity in case of knowledgeable computer users. In fact, I would even recommend against it because of the stress (i.e. file-system level monitoring of files opening/closing/etc.) that it puts on a user's system. But yeah, a good firewall (like for instance XP SP2's, don't ask me why!!) is a completely different matter ...

And as I wrote in my post in the "Anti-virus necessary?": thread on forumu on Ars Technica website:

"Well, IMO the problem in our cases (of computer savvy users) can be that we disable the "real-time" protection (I most certainly recommend this, at least for example during software installations, applying various updates etc.), and so we can be infected then when protection is off.

For instance, I use Avast! anti-virus program, and I enable its "on-access" protection only when I am connected to the Internet, and even then only the "Web Shield" component. As I mentioned many times already, I mostly visit the same set of sites every day, then I practice the "common sense" thing in surfing the web etc. etc., so I haven't got any problem (with a few exceptions, which were all my experimenting's/stupidity's fault) with viruses or any other form of malware for years!!"

P.S., I also touched this issue/subject in great details in this entry: on my slovenian blog; although it's in slovenian language you might understand some parts of it.


best regards,
Ivan Tadej, Slovenia

June 13, 2010 10:03 PM

i want to safe my phone

Miss. Andrea Borman
April 12, 2011 4:50 AM

I have 3 Windows 7 laptops and none of them have any anti-virus software on them. I don't believe in anti-virus software because I think they could cause more problems than solve them. It could give a false reading and tell me I have a virus, when I don't and block access to my other software. On Windows 7 we have Windows Defender and Malicious Software Removal Tool-MRT. And these two tools both scan and remove viruses and malware. But at the same time,they don't take over your computer like an anti-virus program does. That is YOU control how you want these programs to run and when they scan. Andrea Borman.

June 14, 2011 7:24 AM

I'd like to see a 2011 Win7 update to this question...have your thoughts changed, stayed the same, any other thoughts?

McAfee pop-ups from the bundled software from Dell is almost as annoying than an actual virus. "Do you want to buy?" "Your protection is over in a month. Now do you want to buy?" "Now?" "Now?" "Special, 1-time offer--want to buy?" "Same special 1-time offer again--want to buy now?"

And on and on. Any thoughts?

Yes, you definitely still need anti-virus software. Check out What Security Software do you recommend?

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