A few thoughts on Malware detection software (and security in general) from someone in that business.....
Malware detection(sometimes remediation) software is like buying condoms. Some can use the average old stuff and never have an issue, other require a more professional approach. Pick one that works based on your needs and use it consistently. That means registering the software, updating the software, and using the computer with some degree of responsibility.
For Windows operating systems, patching your computer is now a requirement. You should be downloading and installing the latest patches each week. Unpatched systems are the benefit to hackers. Your use behavior determines your risk. If you surf **** you will most likely have some degree of malware regardless of your AV software. Clicking on pop-ups is verboten, period. Opening every email from anybody is another way you get attacked.
A solid layered defense is required today. You need a up to date system, an up to date malware detection/remediation software package, the software firewall turned on, and a physical firewall that is configured correctly. These items combined with responsible use should put you in the 90% covered circle. Yep, its not a 100% coverage.
No one program or hardware will defend you completely. What used to be successful will fall victim at some point in the future. Hardware and software are created by man and therefore are subject to the human frailties inherent in the mortal coil. Security in and of itself on the Internet is but a concept and is NEVER a reality. All defense developed today will fall to the attacker of tomorrow.
I do cybersecurity for a living. I am an active CISSP and CIPP and have worked with the biggest and best (NCR, IBM, Microsoft, Dell as well as the name brand customer in MIC and everyday products and services). We will all experience an incident at some point. Contact me off line and I will be happy to elaborate in a more direct and verbose fashion. In the mean time....be safe.