From PC Tools:

PC Tools AntiVirus Free Edition protects you against the most nefarious cyber-threats attempting to gain access to your PC and personal details. Going online without protection against the latest fast-spreading viruses, worms and Trojans can result in infections within minutes. Once infected, the virus will usually attempt to spread itself to your friends, family and associates by accessing your e-mail contacts and networked PCs. The infection may also allow hackers to access files on your PC, use it to launch attacks against other computers and Websites or to send mass spam email. That's why PC Tools AntiVirus Free Edition provides protection, with rapid database updates, IntelliGuard real-time file, Internet & e-mail protection and comprehensive system scanning to ensure your system remains safe and virus free. Version 5 features new improved scan engine, smaller memory footprint, and much improved system performance.