This thread is to help spread knowledge about the various offerings of "free" antivirus programs out there. There are quite a few more besides the commonly known AVG, Avast, Antivir/Avira, and MSE.

I would like to keep revisiting this thread, updating information as we come across it.

Now, I mostly turn to free AV products for the freebie jobs I do for friends, family, neighbors. And even though I have tons of NFR licenses for many different "big name" brand products from work...I still use MSE at home. So far it has proven to work well for me....but I'll admit, I do have concern about its sinking ratings over the past year. And I wouldn't be good at my job if I wasn't keeping an eye out for other possible replacement products for this product.

Also at work, we focus 99% on business clients, but we have a lot of home users rigs come across our bench to get worked on...and we've been putting on MSE.

I'm aware of the "pay for" products...most of what I work in day to day is with the best of the best of security products, Kaspersky, Eset, BitDefender, Panda, etc. That's a whole separate topic and I don't wish to mix those into this thread which is solely on the "free AV" products. of the biggest concerns for me is simplicity of use, and how easily the end user can keep the product running. By that last point, I mean...basically they don't have to worry about keeping it registered on a yearly basis. Because we all know that home users are horrible about keeping antivirus licenses renewed. I'd rather have a mediocre antivirus product on their rig that is "set it and forget it" for the life of the computer, versus a more effective product that needs to be renewed and/or reactivated on a yearly basis. It is likely the end user will ignore after the first year is up, it expires, it fails to update and protect..and now they're screwed. This right here is the primary purpose that I've liked and used MSE for this type of end user.

I also do not like to see advertisements...or frequent "nags" to upgrade to the pro/paid for version. Some products are guilty of disqualifies them from anything I'll use.

A list of products...lets get a long list together, and I will keep editing this list as new products keep coming in.

360Safe/360 Internet Security/Qihoo360 - Runs triple engines, 360Cloud, Qihoo QVM, and BitDefender. Free for home use only. I installed this on my own laptop yesterday to start testing it, (11/26/13) and so far it's been solid, haven't noticed a performance hit which I did expect from a triple engine. No adware so far.

AdAware free antivirus - Most of us know Lavasofts AdAware adware/spyware removal program from years ago, they added a combo antivirus product also. Haven't looked at yet.

Agnitum Outpost Free -

Amiti Antivirus - An open source clone running on Clamwin

Anvi Smart Defender - Reviews said it's not very effective

AVG - I remember the days when AVG was the free product of choice..back with version 5 or 6....but it really started dropping in effectiveness around version 7 (early XP days?). And I don't like its browser protection bar...seen it cause so many issues. I still see so many computers that have AVG come across our bench from infections.

AntiVir - Pretty decent detection rates, amusing reference to Star Wars in the name of its scanning engine, but horribly high false positive rages. And the constant nags to upgrade to the Pro version drive end users nuts. Frequent reliability problems with the free update clients often lag behind in definitions.

Avast - I've liked its performance in detection rates. Relatively low false positives. A rather quirky interface. But what kept me from liking it was the fact that, last that I knew (I'll admit it's been a few years) you had to keep an account with them and re-register the product yearly.
They currently offer a "Free for EDU" package (educational facilities....added this link on 04/12/2013 and I don't know how long the special will last)

Baidu - Similar to 360Safe, triple engine....Baidu local scan, Baidu cloud, and AntiVir.

BitDefender - They recently released a new free product that does have real time file protection. Unlike their prior version which did not. Very bland interface, doesn't let you configure much. But quite good performance. You do have to register with them once to get an account and that alone makes me think it's not a good option for me to use for this type of client needs.

Commodo - I tried it had frequent problems updating.

ClamWin - relatively ineffective against more modern web based "threats".

CYSEC - Have not tried yet, interesting website. Based in London. Also offer free remote access and network mapping tools.

Digital Defender - Haven't looked at it yet.

DrWeb CuritIt - Haven't looked at it yet.

Fortinet Forticlient Lite - Haven't looked at it in a while.....was a full security suite only, meaning software firewall too.

Immunet - Haven't looked at it yet.

Kingsoft - Haven't looked at yet but feature set looks good

MSE - Came out on the market doing fairly well in reviews, has been sliding in ratings lately, but it really is a "set and forget" product. No registration required, no renewals, no nags, simple interface. It also is unique among the other offerings as being the only "free antivirus" that is licensed to be used in a busines....currently of up to 10x computers. Desktops only, no server operating systems.

NANO antivirus - no info

Panda Cloud Free - Panda has been doing very well in detection of new/rising threats. A cloud based product, as the name illustrates. Just installed on my laptop, no registration required (good). During install there are 3x checkbox options for "me-too ware" wants to put in the Panda Security Toolbar in Internet Exploader and Firefox, based on Blekko search, and it was to set Blekko for the default search engine. As well as set the home page to MyStart. You can opt out of all 3 of those. For the management console, a decent set of features, including file and directory exclusion options.!/...virus-download

PCTools - Haven't looked at it yet.

Returnil -

RisingFree - Haven't looked at it yet.
Appears to have a version which they say is compatible with Server 2003 and Server 2008...

Roboscan - Reviews show as mediocre

UnThreat - Haven't looked at it yet.

ZenOK - Haven't looked at it yet.

Zillya Antivirus -

ZoneAlarm - Haven't looked at it yet.