Microsoft's free antivirus aimed at both beginner and advanced users.
Search for all kinds of virtual pests with this excellent Russian antivirus.

Software that offers comprehensive protection from online threats.
Open source anti-malware security software designed to detect and remove malware and other threats.
Free utility that detects and removes adware, hijackers, toolbars, and PUPs from your browser.
Small program that detects the presence of any type of keylogger on your system.