• Zeus

    I recommend Avast to everyone I know. Low on resources, good at avoiding false positives, never had any trouble.

    On top of that, I usually tell people to install Malwarebytes Anti-Malware. The free version is not a real-time scanner, so you manually run it every now and then, or when you think you have a problem. But it's saved my bacon multiple times. My brother's computer was basically wrecked, crippled with malware, and nothing could save it until I ran Malwarebytes.