Best Free Antivirus Software

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Antivirus software provides an essential layer of protection from viruses, trojans, worms, spyware, adware, dialers, keyloggers, and rootkits. Don't let the name antivirus confuse you. These days every good antivirus has good detection rates for all forms of malware, not just viruses. The term malware includes viruses, trojans, worms, spyware, adware, dialers, keyloggers, rootkits, and any other software which performs malicious activities on a computer.


Sadly, the amount of malware currently in circulation is so large that no antivirus could possibly detect all of it. Despite vendor's claims, no single antivirus solution can detect nearly all new malware. There are some products out there, including some in this review, which include technologies which are able to adequately protect a computer, but any product which relies mainly on detection is statistically doomed to fail at some time. Also, using more than one real-time antivirus at the same time uses much more system resources, can cause system errors, and can even reduce protection. For my advice on how to compensate for these weakness of antivirus products, to a large extent, please see my other article about How to Stay Safe While Online. Having a good antivirus product does go a large way towards adequately protecting your computer, but in this day I would highly recommend that you add additional layers to your security.


Below I have reviewed some of the most effective Free Antivirus products currently on the market. In order to make this review more unbiased, although of course my own intuition and experience does affect my judgment as well, I came up with a particular methodology for comparing these products. This methodology is described in the following section.

Methodology For Comparing Products

The main motivation behind why I came up with this particular methodology for this review is that I value system protection against real world threats above all other categories by which an antivirus is commonly judged. It does not matter to me whether an antivirus protects the user by detecting malware, blocking dangerous sites, behavioral analysis, sandboxing, or any other approach. The most important thing is that at the end of the day your system is safe from infection. Thus, that is the attitude I have taken towards reviewing these products.


Therefore, I found Antivirus testing organizations which claim to test products against situations which resemble real-world situations. I narrowed these down by further requiring that the organizations have a relatively long record of producing good, seemingly unbiased, results. The organizations I ended up with, and therefore used for this review, are:



Dennis Technology Labs

From here I looked at all tests ranging to the beginning of 2013. However, if there were more than three tests within that range I used only the most recent three. Also, if given the choice between results from different operating systems, I chose that for the most popular operating system. At the moment Windows 7 is the most popular operating system.

Also, I only considered results if it was specifically the Free Version which was tested. This is because the results for the Paid Version of the products in this review, with the exception of Comodo Antivirus, are often quite different from those for the Free versions.

In addition, I did not count it against any of the products if they were not tested by multiple organizations. As long as they were tested by at least one, within the above-mentioned period, they were considered. This criteria was chosen because there are many reasons to choose not to participate in a test. Thus, it should not be held against the product if they were not tested by multiple agencies. However, if they were not tested by any, this makes it impossible to compare them in an unbiased fashion.


Once this data was collected, I then looked at the overall results for the Free Antivirus products discussed in this review, and ordered them mainly according to the quantitative results. However, my own knowledge of the products, and the reviews and experiences of others, were also considered. The results are presented and discussed below.

Discussion And Comparison

Comodo Antivirus is my top pick for advanced users or for Intermediate users who are okay with an antivirus software which will occasionally ask them for input. However, if you do not fall into those categories, or for any other reason find it to not be a good fit for you, then you will likely find my next pick suitable. Also, for those who prefer a complete solution, there is always Comodo Internet Security, which is also free and includes a firewall in addition to all other components which already come with Comodo Antivirus.

The reason I made this my top pick for advanced users or users who are okay with a somewhat talkative antivirus software, is because it is the only product which I feel confident saying that it will protect you against nearly 100% of real-world threats. I have a lot of experience with this product. I am a volunteer moderator on the Comodo forums and have been using it for a long time. I know this product very well, and am entirely confident in its ability to protect.

Comodo Antivirus uses the cloud to facilitate the detection of the most recent malware, as do many other Free Antiviruses reviewed in this article. However, Comodo also incorporates a Behavioral Blocker, which will automatically sandbox all software which it does not know for sure is safe. Thus, the user is protected from nearly all malware, which will either be detected by the antivirus component or sandboxed by the Behavioral Blocker. It will also analyze unknown applications for suspicious behavior, and alert the user accordingly.

However, as mentioned previously, users who do not want a somewhat talkative antivirus should continue to my next pick. Also, by default Comodo Antivirus has small advertisements (which can be disabled as shown here). Also, during installation users should be sure to click the Customize Installer option, which is near the bottom-left of the installation window. This will allow them to uncheck additional software, which the installer will automatically install with Comodo Antivirus unless unchecked. This software is not dangerous and includes a browser, and ad-blocking addon, and an optional paid service which would allow Comodo technicians to assist you with any computer problems you have. These, and a later option to change your homepage to support Comodo, can safely be unchecked during installation. Even with this extra hassle, this software is still my top pick, but I do wish they made the process simpler.


Avast! Free AntivirusAvast! Free Antivirus is has very good protection rates. Avast has many different protection shields, boot-time scanning, a behavioral blocker, an internet site ratings plugin, script malware protection, and access to cloud-based protection. It's arguable whether their ratings plugin offers comparable levels to WOT, but the script malware protection can prevent certain browser exploits, a feature not available in any of the other free AV's reviewed.

Avast is also relatively light on resources. However, do note that Avast requires a free registration to function after 30 days, and the default installation installs the Chrome browser unless you uncheck it.


Panda Cloud AntivirusPanda Cloud Antivirus is another excellent choice for average users, who may find both Comodo Antivirus and Avast too confusing. It has a simple interface, completely automated features, access to cloud-based protection, and has been shown to be very good at protecting a computer. Panda Cloud Antivirus has a behavioral blocker, web protection, and access to cloud-based protection, all of which will help increase your security.


AVG Anti-Virus Free EditionAVG Anti-Virus Free Edition is also a decent choice for average users. My analysis of the results, as discussed in the methodology section, does show that it does a decent job of protecting your computer. However, it appears that the above Antivirus products tend to do better. Also, it comes with advertisements (but they can be disabled).


Avira AntiVir Personal EditionAvira AntiVir Personal Edition is another product which has a very good reputation. However, the free version was not tested by any of the three testing organizations I referenced in my methodology. Therefore, I cannot currently recommend it above any of the previously mentioned products.

However, other comparative tests do show that it has very high detection rates for malware. Also, many users have used it and found that it is very effective. Also, users have access to cloud-based protection. AntiVir is certainly a good choice for a free antivirus, but due to the lack of real-world testing, at this time I cannot recommend it above the other products in this review. Hopefully in the future they will have the free version tested by these organizations as well.


Bitdefender Antivirus Free Edition

Bitdefender Antivirus Free Edition is another free antivirus product which has a very good reputation. However, the free version was not tested by any of the three testing organizations I referenced in my methodology. Therefore, I cannot recommend it above any of the previously mentioned products.

The engine for this product appears to be the same as for the commercial product. However, the level of protection provided has not been shown identical with the paid version, which is why I did not use the results for the paid version in my analysis. The user interface for this product is very minimalist. Thus, it may be attractive for novice users, though more advanced users may be frustrated at the lack of customization. Bitdefender Antivirus Free Edition is a good choice for a free antivirus, but due to the lack of real-world testing, at this time I cannot recommend it above the other products in this review. Hopefully in the future they will have the free version tested by these organizations as well.


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Quick Selection Guide

Comodo Antivirus
Gizmo's Freeware award as the best product in its class!

Runs as a stand-alone program on a user's computer
This has full real-time protection capability, including real-time antivirus, behavioral blocking features, cloud-based protection, and an automatic sandboxing function which protects users from nearly all malware.
The automatic sandboxing function, although not very intrusive, may be too talkative for some users. Also, by default non-intrusive advertising is enabled (although it can easily be turned off).
Version 6.x
32 and 64 bit versions available
Unrestricted freeware
There is no portable version of this product available.
Windows XP, Windows Vista, Windows 7, Windows 8.x

Take care to avoid the installation of unwanted software during installation. To do this use the customized installer button, which is on the lower left-corner of the screen during installation. Additional software, including a browser, an ad-blocking addon, and an option paid service which would allow Comodo technicians to help you with computer problems, are all included by default.

Avast! Free Antivirus
Runs as a stand-alone program on a user's computer
This has full real-time capabilities, behavioral blocking features, script malware protection, and a low rate of false positives.
Default settings require certain user interaction. Bundled with Chrome browser by default (see notes).
Version 9.x
32 bit but 64 bit compatible
Feature limited freeware
There is no portable version of this product available.
Windows 2000, Windows XP, Windows Vista, Windows 7, Windows 8.x, Mac OS

Take care to avoid the default inclusion of Chrome browser during the install process by using the custom install option. The attempt to install Chrome will also be repeated at the program update if the automatic option is chosen.
Quick Start Guide:

Panda Cloud Antivirus
Combines a web service with a stand-alone program
High detection rate of malware, web protection, some behavioural blocker features
Detection rates of real-world malware is slightly lower
Version 2.x
32 and 64 bit versions available
Free for private use only
There is no portable version of this product available.
Windows XP, Windows Vista, Windows 7, Windows 8.x
AVG Anti-Virus Free
Runs as a stand-alone program on a user's computer
Behavioural blocker
Slightly lower signature detection rates
Version 2013.x
32 and 64 bit versions available
Free for private use only
There is no portable version of this product available.
Windows 2000, Windows XP, Windows Vista, Windows 7, Windows 8.x

Forum for support

Avira AntiVir Personal Edition
Runs as a stand-alone program on a user's computer
Outstanding detection of malware
Not the most user friendly
Version 14.x
32 bit but 64 bit compatible
Free for private use only
There is no portable version of this product available.
Windows 2000, Windows XP, Windows Vista, Windows 7, Windows 8.x
Bitdefender Antivirus Free Edition
Runs as a stand-alone program on a user's computer
High detection rates, very user friendly
Lack of customization
Version 1.x
32 bit but 64 bit compatible
Free for private or educational use only
There is no portable version of this product available.
Windows 2000, Windows XP, Windows Vista, Windows 7, Windows 8.x


This software category is maintained by volunteer editor Chiron. Registered members can contact the editor with any comments or questions they might have by clicking here.


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by Anonymous on 16. December 2008 - 15:52  (11965)

thank you. thank you. thank you.

You just resolved my only issue with best free AV.


by Anonymous on 12. December 2008 - 11:01  (11807)

Thanks JonathanT, I truly appreciate it a great deal...fine job you and the rest are doing here, excellent!!

by JonathanT on 12. December 2008 - 13:58  (11813)

Thanks for the kind words!

by beebrooke39 on 9. December 2008 - 16:36  (11690)

The "big 3" in the Free AntiVirus line up namely AVG...Avast and Avira all have their plus points and minus points as do all applications!! Users have to remember that programmers have to cover a huge area of different setups on loads of differently configured machines and this can cause different behaviour across the wide platform of machines where these programs are installed!!
This naturally accounts for the huge variation in peoples experiences with various programs and also the varied reviews we see on many sites.."Best program ever!" "Crashed my machine..Don't go near this application!" These are just a couple of examples of the many of reports that we see which make it a difficulty for new users to select the best options .
I have used all three of the above A/V applications and all have performed well and on some occasions after adding other software or making adjustments to browser settings or configurations..I have noted a change in performance of the AV program scanning speed or other minor glitches.
If this happens ..I uninstall and try either of the other programs and monitor the performance .It sometimes means switching between them occasionally and many new users or beginners will not want this hassle I know...but its a fact of life when adding software of whatever type!!..
Moral is ..If it works for you and does the job it was intended for ..then Great! If it causes slow downs or any other negative issues..Try another alternative.I used "Avira" for years ..and then after some configuration changes on my machine ..It was hopeless!! ....The right horse for the right course is the maxim here methinks !

by Anonymous on 9. December 2008 - 20:05  (11695)

Agreed, but these 3 might have to pay a bit more attention to what they are doing in the near future. I almost completly agree with what you are saying about the fact that different software can work differently on differet computer set ups, but the fact of the matter is that AVG has always had some sort of installation problems since I first used it. Avira always seems to have issues with updates, and Avast has issues with false positives and in my opinion, lack of control unless you know your way around a computer quite well, although you can generally find answers by google-ing them. Now, don't freak out on me because I am saying this, but there a quite a few other free AV's that are starting to close the gap between them and the "big 3". For one, Rising is generally trouble free and there seems to be a slow trend of it getting better, it still has a long way to go, but it seems to have alot of the software problems solved. PC tools AV is also catching up and it's a nice lite AV. Comodo AV is catching up with it's rates quite quickly and there are very few problems with that scanner except it sees no need to scan email or the like, which prevents bloat. I'm not saying drop what you are using and go for one of the ones I have mentioned, all I'm saying is that AVG is becomming more and more complex and more and more bloated creating problems on it's own not to mention the installation. An av is only as good as it's updates and Avira has issues with that, there were many days where I could not get it to update. And Avast (the one I would recommend) has it's faults as well. For someone new to the program it can be a bit of a daunting task to use it right now cause of the media style HUD, and even the skins aren't much better and in some instances give less information and make it harder to access different things. Plus their alarm sound when something is found sounds like D-Day for the computer and literally freaked out of my wife to a point where she wouldn't go near the computer in case she made a mistake and the computer went kablooey!. Either way you go, you should always use one of the on demand scanners mentioned at least monthly cause none of these AV's are 100% and the last time I had AVG installed I became infected and luckly Kaspersky's on demand scanner came to the rescue.


by jgodfrey on 9. December 2008 - 15:55  (11687)

As a long-time Avast User, I know it's great software though I can sympathize about the "funky media player style interface" mentioned in the original article.

Thankfully, the application is skinnable and there are a number of more "normal" skins available on the Avast site. Even with a new skin though, the GUI is still a bit odd and could really stand a face-lift, which I understand is in the works for V5.


by Anonymous on 7. December 2008 - 17:00  (11585)


by Anonymous on 7. December 2008 - 12:29  (11572)


by Anonymous on 5. December 2008 - 4:22  (11476)

I have a new computer (8GB, 64b Vista) that came with Norton Internet security - which I am replacing as the 60 day license is almost up. I used to use AVG on my XP machine, but was less than impressed so was looking for something else. In installed Adaware, it stalled on a particular InstallShield file (don't recall which one) after about 4 hrs until I killed it. I have installed Avira and it has been running a scan now for 12 hrs 8 min and is still not finished - it seems EXTREMELY slow in scanning afm and other font files - has been at 99.8% complete for over 90 minutes. In contrast, the Norton scan took about 4.5 hrs.

Any suggestions?

by Anonymous on 7. December 2008 - 11:31  (11568)

Try avast instead of avira, and uninstall norton, it works with 64bit and i find it the best anti-virus i've ever used

by Anonymous on 7. December 2008 - 3:13  (11551)

You are running multiple AV programs, aren't you? You can't do that!!

by Anonymous on 6. December 2008 - 6:42  (11517)

You need more than CC, your PC's infected and your registry is corrupt. Perhaps the site or forum mod in here can suggest something.

by JonathanT on 6. December 2008 - 12:44  (11527)
by Anonymous on 6. December 2008 - 3:26  (11514)

Uninstall all your previous antivirus and stick to Avira.

Run Ccleaner:

Reboot you pc in safe mode.
Run MalwareBytes AntiMalware:
Run Avira - complete system scan.

Good luck

by Anonymous on 3. December 2008 - 16:20  (11373)

i recently recieved viruses and multiple cookies trojan horse vundo AQ ..fake
alert viruses..etc. i have xp home edition 2002 and ran avg 8.0 numerous times
in both regular mode and safe mode some of the viruses cannot be moved to vault
or deleted unless i system restore point could not function and i
have turned it off..i now get pop ups in which befor i didnt and some explorer
sites i cannot access or update my firewall also shows that updates are
off and wont allow me to turn on...i have also tried running in last know good
config but to no comp is exremely slow on start and usually freezes
and i must reset 3 or 4 times befor i can get it to run...and when it does run
it freezes up causing me to reset again...plz help

by Anonymous on 4. December 2008 - 22:16  (11462)

1) Use
'Kaspersky Virus Removal Tool'
'Dr.Web CureIt'
to clean your already infected PC.
Once you clean your PC,

2) Replace AVG with
either 'avast! Home Edition' (Free)
or 'AVIRA AntiVir Personal Edition' (Free)

-ALSO have another Backup Scanner (=On Demand):

3) Install
either A-Squared 3.5 AntiMalware (Free)
or SUPERAntiSpyware Free Edition

by Anonymous on 3. December 2008 - 21:49  (11388)

How did you get all of that all of a sudden? Anyway, it does sound like you will have to format your hard drive and reinstall windows. Do you by chance use internet explorer? If you do then you seriously might want to try Firefox or Opera, Safari is also good but it is singled out a bit more but it gets updates very often. That might help. Another thing you can do is set up your browser to delete cookies when you exit the program. Or at least set it to only accept them from sites you are visiting. You might want to try Avira instead of AVG as AVG has been having issues ever since 8 surfaced. Even on powerful computers it is a hog and when you experience slow down like you did then that can make the AV practically useless. Also you should have a good Antispyware program on your computer, either SAS (SuperAntiSpyware) or MBAM (MalwareBytes Anti-Malware), unless you pay for them they are only on demand scanners, but you can set them to scan and update automatically with windows schedueler or in the programs them selves. You might even want some memory and registry protection both of which you can get for free from Comodo. Well, good luck, hope it all goes well.


by peter on 3. December 2008 - 17:12  (11376)

Your system sounds as if it's so corrupt that the only sensible remedy is to format the hard disk and re-install windows. XP System Restore is notoriously poor at restoration.
This is one reason why we recommend "disk imaging", "partitioning" and use of an external usb drive for "backups".
Try searching this site using those terms for more info.

by Anonymous on 3. December 2008 - 6:14  (11352)

Just had to restore my entire computer from scratch using disks after attempting to remove CA antivirus+. I'm not sure if this is just my vista configuration that caused the crash or not, but It did cause my system to completely fail causing me to have to do a complete restore from recovery discs. I'll stop posting comments and let someone read them now. Kendell.

by Anonymous on 2. December 2008 - 5:09  (11299)

Ok, this should be my last comment tonight. Has anyone heard of Ca antivirus? I've run across it on the web a few times and I haven't heard of it. Has anyone used it? It's certified by icsa and vb, so that's good.

by Anonymous on 2. December 2008 - 3:40  (11296)

one more thing, if someone helps me, I'd prefer an antivirus that's been certified by one of thevirus testing sites, or have good scan scores. I've downloaded and subsequently uninstalled hundreds of antivirus programs that said they had what I needed and ultimately turned out to be either scams, or unaccessible. My fiance even baught one without checking it out or trying, just bought it and it wasn't effective, and had no realtime protection. I think it was called "antivirus and trogen." I'll shut up now before I annoy someone. Kendell

by Anonymous on 3. December 2008 - 10:43  (11359)

most other products then these tests r fake or suck.

by Anonymous on 2. December 2008 - 18:44  (11325)

If you are going to buy any go for Kaspersky or BitDefender. They are two of the top rated pay AV's, and they come fully equiped if you get the internet security suites. Firewall, AV, AS, malware, rootkits, realtime scanning, email scanning, and pretty much everything else.


by Keyur on 10. December 2008 - 3:46  (11707)

Bit defender is my favorite as far as commercial products are concerned. it's even better than Kasperky . the problem with kasperky is, it slows down PC. Bit defender is light on resources and has excellent detection rate.


by JonathanT on 3. December 2008 - 7:34  (11355)

I've heard the Norton 2009 products are also excellent.

by Anonymous on 11. December 2008 - 2:25  (11742)

Norton has a poor track record in terms of heavy resource use and slowing systems down. If you are planning on purchasing a Norton security product, I highly recommend you try a demo/trial version first. See how it works on your system and if you think it is right for you.

Better yet, there are great free versions of antivirus, firewall, etc...(which are well documented on this site) and you can easily get better protection by combining a few of these free programs.

Anyhow, Norton has gotten a lot of bad press about their past products, but the 2009 versions MAY be an improvement (I personally think the 2009 products are not up to par, but check it out for yourself).

by Anonymous on 2. December 2008 - 3:27  (11294)

Hello. Can someone help me find an antivirus that has realtime protection and scheduling? I've tried all the recommended software on this page and google searched but kept uninstalling the ones I found for one reason or another. I am blind and some of the products (avast, AVG, and avira conflict with my screenreader, either they think it's malware and refuse it, or the screenreader simply refuses to read the UI. I've tried PC tools antivirus free edition and that's completely visually oriented, too many clicking with the mouse. Comodo internet security is also unusable for the same reason. I want to find a program I can stick with and would prefer not to reregister if possible like avast requires. I tried one other, Rising antivirus, and that was a fllp, not accessible. it's a very obscure program based out of china, I think and I don't recommend it. Sorry about the long comment but I need someone to help me find an antivirus program that I won't uninstall in a week. Accessibility is the key, if I can't use it I won't keep it. If it will help, I'm using windows vista home premium, intel t7100, 32 bit, 1.80ghz, 2GB ram, and 160gb Hard drive. any help would be appreciated. The program doesn't have to contain antispyware capabilities since I have malwarebytes. antimalware. Kendell.

by Anonymous on 10. December 2008 - 3:30  (11706)

ThreatFire is a program that is behavior-based vs most programs which rely on definition updates. This program does not need definitions. There is a way to get it free, but it involves choosing one of their advertisers, which you'll probably have to try.

Another such program is mamutu, $30 for one year. which

Before trying them, I'd write to these people, asking them about possible conflicts with your reader. I just thought that since these programs are different, they might not conflict.

by JonathanT on 2. December 2008 - 12:36  (11306)

Hi. I don't know exactly what you need but have you tried McAfee from AOL? It's got realtime protection, but I'm not sure about scheduling and accessibilty.

by Anonymous on 2. December 2008 - 14:13  (11309)

It's no longer free. Now you need a payed plan.

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