BEST FREE ANTIVIRUS DOWNLOAD

Avast! Free Antivirus is my new top pick for the best free antivirus software in light of recent developments. Avast has steadily been improving its detection rates over the past few years and now ranks with the some of the best. Avast has the most features of all the free antivirus with full real-time capabilities including web, e-mail, IM, P2P and network shields, boot-time scanning, and a behavioural blocker. The new  version 6 brings even more features including an internet site ratings plugin, script malware protection and a limited (non-configurable) sandboxing feature. Although the sandbox is a very useful semi-automated security feature, the default settings involves a pop up to ask whether a software should be sandboxed for not - for the typical average user this can be slightly confusing though it can set to sandbox the software automatically. Lastly Avast is relatively light on resources.


Microsoft Security Essentials is a favorite of mine with great detection rates, particularly for rootkits. Even more impressive is the fact that Microsoft Security Essentials has very few false positives, is light on resources and is good at removal of existing malware. MSE is a great choice for average users because of the minimal user interaction required. It automatically updates and removes threats. No registration is needed, apart from a quick validating of Windows, and there are no nag screens or advertisements.
The main downsides are the slow scan speeds and the lengthy amount of time it takes to quarantine malware, though in my opinion these are rather trivial concerns, as for example a scan just be run overnight. MSE also is not available in certain countries so users there will have to look elsewhere. Note that Microsoft Security Essentials requires a genuine copy of Windows to install.


Panda Cloud Antivirus is Panda's successful attempt to jump on the free antivirus bandwagon. Along with MSE, it is an excellent choice for average users with a simple interface and completely automated features with automatic updating and removal of malware. The detection level is generally very high, but according to the latest test data, detection of zero day threats is slightly lower. PCA uses 'cloud' technology to provide for a much quicker release of updates as all definitions are stored in the cloud and thus the moment Panda updates their blacklist all users of PCA with an internet connection are protected from it.
Panda Cloud Antivirus has a behavioural blocker and web protection, which will certainly increase your security. However as you can simply use one of the other free AV's with a separate behavioural blocker (for further details see our Security Wizard) to achieve possibly even better protection, this is not necessarily an advantage.
One minor reservation I have is that PCA seems to erroneously detect certain browser/system-related applications, for example VideoCacheView, and because of the automatic quarantine this made it a fraction bothersome.


Avira AntiVir Personal Edition is another high quality free antivirus, and formerly the Top Pick. The primary reason I removed it from its status involved the recent controversy of AntiVir including a re-branded Ask toolbar in their installer, and a temporary spate of advertisements promoting a possible 'scareware' company. In spite of the negative press though AntiVir is still a top notch antivirus scanner with outstanding detection rates of malware, higher than almost every other antivirus according to tests. AntiVir is still a good choice for a free antivirus scanner, particularly for high risk users.
However, there are some minor reservations. First, AntiVir does not include web or e-mail scanning capabilities; this is only available in the paid version. The lack of an e-mail scanner is not a disadvantage, it just means that AntiVir won't warn you of infected emails before you open them. But should you open an infected email, AntiVir will still spring into action, so it doesn't mean that you're not protected from email-based infections. Also, AntiVir contains a rather intrusive advertisement every time it updates. Although AntiVir had signature updating problems in the past, this issue seems to be fixed now.


AVG Anti-Virus Free Edition is also a decent choice for a free antivirus. Although this venerable antivirus has had some shaky results in detection in the recent past, it now offers a high level of protection. This is probably due to the inclusion of a fully-fledged behavioural blocker that is the "Identity Protection" protection. This provides a very important additional layer of protection, on the other hand though a similar protection level can be achieved by using one of the free antivirus above alongside a separate behavioural blocker. Unfortunately AVG free has grown considerably in size, has very slow scan speeds and also advertisements (but they can be disabled).
These free antivirus programs are excellent software that provide a real alternative to the major commercial antivirus products.