Security Essentials from Microsoft is definitely one of the best free antivirus programs available right now. Microsoft is relatively new to the antivirus game but don't let that scare you - Security Essentials is a fantastic antivirus program that protects you from all sorts of malware, updates automatically, and is incredibly easy to use.
Microsoft Security Essentials (MSE) supports Windows 7, Windows Vista, and Windows XP. The anti-malware protection in MSE is part of the built-in Windows Defender tool in Windows 8.
Two of the biggest reasons I added Microsoft Security Essentials to this list of the best free antivirus software is because it's available directly from Microsoft and also because it's very easy to see if you're computer is secure from threats: if the icon next to your clock is green, you're good; if it's red, something is wrong.
Panda Cloud Antivirus Free 2 protects you from several kinds of malware threats - viruses, worms, Trojans, adware, and more - just like all the other free antivirus programs in this list.
What makes Panda Cloud Antivirus Free 2 one of the best free antivirus programs is that it does its job from "the cloud" meaning the hard antivirus work that typically slows down a computer is done on computers elsewhere on the Internet, freeing up your computer to work like it should and protecting you from malware even better.
Panda Cloud Antivirus Free 2 supports Windows 8, Windows 7, Windows Vista, and Windows XP.
Tip: Panda Cloud Antivirus Free tries to install a toolbar and change your browser's home page and default search provider during the installation process. Uncheck those boxes before continuing if you don't want them. None of those changes are required to use Panda Cloud Antivirus.
Rising Antivirus Free Edition is the free antivirus offering from China's largest antivirus maker, Rising Software.
Rising Antivirus Free Edition (version 23) works with Windows 7, Windows Vista, and Windows XP.
While I doubt that Rising Antivirus Free Edition would top anyone's list of the most attractive antivirus software interfaces, it does appear to be updated frequently and it was easy to use.
UnThreat Free AntiVirus 2014 offers standard malware protection, including threats via email. I found nothing too impressive about this program aside from its price... or lack thereof, I suppose.
UnThreat Free AntiVirus 2014 (version 6) works in Windows 8, Windows 7, Windows Vista, and Windows XP.
For the most part, I found the installation and use of UnThreat Free AntiVirus 2014 on par with most of the other best free antivirus programs I've profiled here. My favorite thing? UnThreat didn't try to install extra software or toolbars during installation, nor were any of my browser settings changed. While that should be commonplace, it's not, and it was appreciated.
Zillya! Antivirus is another free antivirus program that works with Windows. It's nearly the same as most of the other programs from this list.
It actively scans emails and USB devices, and you can choose a quick, full, or custom virus scan. There's an exclusions category so you can remove certain folders and/or files from being scanned.
Update are automatically ran every few hours to ensure the databases are current, which is nice. However, what's not so nice is the fact that the installer is pretty large, at nearly 115 MB.
Zillya! Antivirus has a few extra features like a built-in task manager and startup manager to disable startup items.
Setup is really quick and doesn't contain any extra software or toolbars, which is a plus.
ZoneAlarm Free Antivirus + Firewall 2013 is just that - a combination free antivirus and firewall tool.
Check Point Software, the makers of ZoneAlarm Free Antivirus + Firewall 2013, have been in the firewall business for a long time. They make good software and this program is no exception. While I didn't notice anything spectacular about the antivirus portion of this program, having an antivirus and firewall tightly integrated has its benefits.
ZoneAlarm Free Antivirus + Firewall 2013 supports Windows 8, Windows 7, Windows Vista, and Windows XP.
Tip: Be sure to choose the Custom Install and then click the Skip all offers link to avoid installing the toolbar and changing your browser settings.
Which Free Antivirus Program is the "Best of the Best"?
As you can see from my list above, there are several fantastic free antivirus choices but which one really does the best job at preventing your computer from becoming infected?
Luckily, a company by the name of AV-TEST independently examines a number of free and paid antivirus programs and ranks them for protection, repair, and usability.
See their Detailed Test Reports for rankings. Antivirus makers regularly update their programs so AV-TEST publishes updated test results every few months.