Your reply is highly appreciated. I am a “non-expert” with 30 years in front of the keyboard. I am retired now, but I cannot think of a day without my computer. Internet is a new world, but brings us some draw-backs... We really want to avoid the malwares. Your explanation of “on access” and “on execution” is understandable, but does not both Norton and Kaspersky have “on execution features”? Quote from Kaspersky: Potential threats are monitored and analysed – in real-time – and dangerous actions are completely blocked before they can cause any harm. In addition to scanning for vulnerabilities, Kaspersky Internet Security 2013 analyses and controls the actions of programs that have vulnerabilities – so they can’t cause any harm. Quote from Norton: Viruses and other security threats can be detected during a manual or scheduled scan. Auto-Protect detects these threats when you perform an action with an infected file. Threats can also appear during an instant messenger session, when you send an email message, or during a manual or scheduled scan. Security risks, such as spyware and adware, can also be detected when these activities are performed.