Ad-Aware Free Antivirus + 

Ad-Aware Free Antivirus+ is a program that doesn't update often, but still manages to keep its relevance. It's an antivirus solution that helps you protect your computer in a comfortable and easy way.

The program has a pleasant-looking interface with bright cheerful colors. The interface gives you access to various functions and features of the program, such as a thorough computer scan with very reliable results identifying existing and potential threats; real-time protection against online and other threats; a Web companion that protects you browser against being affected by viruses and spyware and blocks malicious URLs; a special tool for email protection and control; a network protection tool for multiple machines. There is a notification center for helping you deal with possible threats, a help center to learn the best ways to do that and an app manager that helps you protect and manage security of certain programs.

The only possible disadvantage I can see is a lack of phishing protection. But Ad-Aware Free Antivirus+ makes up for it by being as fast and stable as possible. It can be run as a background application and it does a good job at protecting you from present and future threats.