STOP USING 3RD PARTY SECURITY AND ANTI-MALWARE TOOLS...
1) They are often less secure because they create more 'security' entry points. Creators of malware can look for an exploit in the 3rd party software easier than they can in Windows itself. There is also less chance of the 3rd party software fixing these holes as fast as Microsoft, or fixing them at all, if they never notice or don't care existing customers.
2) They create instability. Most 3rd party software is doing things that they should NEVER be doing on Windows. Few of them ONLY use the MS supplied APIs, thus they hook into the network and FS and I/O drivers. The reason Microsoft started bundling Anti-Malware software is they were noticing that a massive 85% of issues and crashes and instability that users were facing, were directly related to 3rd party Anti-Malware products.
3) Performance - Never install anything that is real-time which turns off Defender or the Windows Firewall. This is something you cannot always test for, as you have no idea where the performance issues or flaws will show up. For example: With one product just a few years ago seemed fine, until our techs realized that when running 16bit software, early VB based software, newer .NET software, and even Win8 Store Apps, that this product made Windows nearly 500 times slower just reading the executables. This type of condition is rather common with most tools, and it could be your favorite game that is suffering load times and you won't realize that the 3rd party software is slow reading its content or that it may be just interfering with Windows caching system that creates huge slow downs.
4) If you are a 'tech' person that helps friends or family with Malware and you notice that Defender is not catching potential Malware, run the Offline version, as it runs in a way that Malware cannot actively hide. Lookup/Search: Windows Defender Offline - It is also the smart way to attach external volumes that you think have malware and don't want to risk infecting your installation.
5) Microsoft understands Windows better than anyone, and it is in their best interest to keep it malware free, and for Defender and the other technologies to not interfere with Windows.
6) With Windows 10's, there is no longer a delay in getting definition updates. This was the only problem with Windows 8, as it wasn't setup to do faster 'definition' updates and Microsoft had no way to push these updates to Windows 8/7; however, with Windows 10 they now can. (This is also why MSE/Defender on Win7/8 would score lower on the 'response time' tests, since the definitions had to rely on Windows Update's schedule.)
Over the years, working in many segments of the security and tech world, I have a war chest of horror stories about Anti-Virus/Anti-Malware/Security software from EVERY company you can name.
It is the year 2016, and the best and safest experience is to leave this to Microsoft and not worry about. If you want to know what Microsoft thinks, just look at the Microsoft Store, where computers are not allowed to use 3rd party Malware/Security tools because of the security holes and instability they create. (aka 'Signature Editions')