I found this particularly useful and insightful not just because Microsoft have upped their game but because Windows defender, the free in-built antivirus from Microsoft that we all love to ignore has been proven to be more effective than the likes of Norton antivirus and Eset. We've all loved to hate Microsoft's free Windows Defender software—it's been so mediocre that it's been considered the baseline metric in third-party tests. But recent independent tests show it's actually outperforming a number of third-party suites, some of which charge you money to use them.
Results released by AV-test.org for the month of December put Microsoft right in the middle of the pack of its list of antivirus software for home users

From the image below, I laughed in Chinese when I noticed the absence of Norton on the list. More amusing is the position of Eset. Norton is one of the most used paid antivirus in Naija. You might wanna look at this post before taking a decision about the effectiveness of Windows defender, and if you must go somewhere else, just make sure you are not paying for what your free windows defender is better than.
Just so you know, I have not used a third party antivirus on my PC in two years.
Source http://www.timigate.com/2016/01/windows-81-microsoft-windows-defender.html#more