Antivirus software provides an essential layer of protection from a multitude of virus, trojan, worm, spyware, adware, dialer, keylogger and rootkit infections. Traditionally antivirus programs just detected viruses and spyware removers just detected spyware but nowadays the boundary between antivirus and spyware removers is unclear. Most current antiviruses have at least reasonably good detection rates of all forms of malware.

Malware includes viruses, trojans, worms, spyware, adware, dialers, keyloggers and rootkit threats that perform malicious activities on a computer. With the huge increase in malware, antivirus software cannot keep up with detecting all of it. But using more than one real-time antivirus uses much more system resources, can cause conflicts and even reduce protection. So I recommend you only choose one antivirus for real-time protection. Instead, you can increase your protection using other security software.

Avira AntiVir Personal Edition is my top pick for the best free antivirus software if you're looking for the best protection against virus, spyware and rootkit threats. AntiVir is very light on resources and the detection rate of malware is outstanding, better than almost every other antivirus according to tests. 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 really 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. Although AntiVir had signature updating problems in the past, this issue seems to be fixed now.

Microsoft Security Essentials is my personal favorite; with good detection rates, particularly for rootkits. Even more impressive is that Security Essentials has very few false positives, is light on resources and is good at removal of existing malware.

Microsoft Security Essentials 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. 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.


Avast! Free Antivirus is also an excellent free antivirus that is very popular. The antivirus detection rates is on par with AntiVir and Microsoft Security Essentials. Avast has the most features, with full real-time capabilities, including web, e-mail, IM, P2P and network shields, boot-time scanning, and a behavioural blocker. Avast is also light on resources. The newly released version 6 brings even more features including an internet site ratings plugin, script malware protection and a limited (non-configurable) sandboxing feature.

These free antivirus programs are excellent software that provide a real alternative to the major commerical antivirus products