When it comes to anti-virus software, there is not reason why anyone should not be protected from the dangers of the Internet. There are many free anti-virus software application that do a good job of detecting and removing malware for free. Below is a quick list of some of these application.
Microsoft Security Essentials (Recommended)
Avast Anti-Virus with anti-spyware
AVG | Free
Immunet Free Anti-Virus
PC Tools Anti-Virus Free
Note: Some of the application offer a “trail” of their upgraded products but it not necessary to participate in the trail to use their free version of the product.