Top 5 Free Antivirus(not the usual free ones)

The word "Antivirus", simply means a software that prevents virus infection. Virus in the computer/electronic world is pervasive. A virus is a program developed for "evil" purposes in most cases. A Virus finds its way to your computer, smartphone and does damage to your device or steals information from your devise. This is where Antivirus programs come in. There are free Antivirus programs for home users that don't do lot of internet connectivity, but for corporate organizations, a free version of an Antivirus will do no good, because it is limited.
Most of the time a free antivirus software is intended only for non-commercial, personal home use while academic institutions, business, commercial, corporate or government use is prohibited. You or your company can be heavily fined if it’s discovered you’re breaking the license agreement.
Below is a lit of free non-commercial/home use antivirus(not the most popular and common, but their really good.

1. Comodo Antivirus / Internet Security
Both Comodo Antivirus and Internet Security can be used for commercial and personal use. This license agreement is stated very clearly in their EULA document that can be downloaded from Comodo’s official website. Visit the link below, click on Comodo Security Solutions, Inc. tab and finally click on Comodo Internet Security or Comodo Antivirus EULA PDF document. Refer to point number 2.1 in the second page of the PDF file. Take note that they have specific license agreement for every version number. So make sure you check that the terms of use remains the same when you’ve upgraded to a newer version.
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2. Immunet

The free version of Immunet antivirus doesn’t have any restriction in usage at all. You can use it for both personal and commercial purposes at any place including office, servers, education facilities and etc. You can find this statement on ClamAV’s FAQ webpage question number 4. Both ClamAV and Immunet have been acquired by SourceFire which is why you’re seeing Immunet’s FAQ posted on ClamAV’s website.
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3. NANO Antivirus
NANO Antivirus can be used without any restrictions and this information is posted at their website in License Agreement page.
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4.Microsoft Security Essentials (Partial)
Many people would have thought that Microsoft Security Essentials is free to use without any limitations as long as the Windows operating system is genuinely licensed but unfortunately their licensing terms say differently. According to the first point in the Microsoft Security Essentials license terms page that is posted on their website, you are only allowed to use the software on up to 10 computers if you operate a small business. MSE usage in Government or academic institutions is restricted.
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5. UnThreat Antivirus
UnThreat Antivirus EULA didn’t contain very clear terms of usage stating that their free antivirus can be used on commercial. We’ve contacted them using their official contact form asking them if their free antivirus can be used for corporate, commercial or educational facilities. 5 days later we received a reply from them confirming that the free version of UnThreat, may be used without any licensing fees.
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You can try out their free versions, if you like them, you can buy the corporate versions.
You are welcome to add to the list any other Antivirus program you feel should be here.