Comodo Antivirus is a powerful antivirus engine which aims to keep your PC safe from even the very latest malware.
The suite allows known safe applications to access your system. Untrusted programs are run in an isolated environment where they can't do any harm to your system, while cloud-based antivirus and behaviour monitoring quickly detects even brand-new, undiscovered threats.
Most of this works entirely automatically, and novice users can simply carry on using their PC just as they did before.
But if you need more control, there's plenty to explore. You can monitor process activity in an extended Task Manager; there's a configurable sandbox for running suspect applications; a versatile Host Intrusion Protection System helps you define exactly what programs can (and can't) do on your system, and a host of settings and options ensure the program works exactly as you'd like.