NoVirusThanks OSArmor: An Additional Layer of Defense SysHardener: Harden Windows Settings VoodooShield
The great thing about Windows Defender is that it plays well with almost every 2nd security app. It's totally your pick. Since you already are using Windows Defender, why not get the most out it? Use Andy Ful's ConfigureDefender tool. https://github.com/AndyFul/ConfigureDefender
Zemana AntiMalware Premium SUPERAntiSpyware Professional Malwarebytes Premium Malware Hunter Pro HitmanPro.Alert
Right, this discussion has really veered off track. The original poster asked what security softs are good complements to WD? And the answer is a wide open field, because they all are. How good are they? Each should be discussed in its own appropriate thread, otherwise it's total chaos.
All of the products I listed (except for Malware Hunter) offer trials. I encourage you to try them for yourself.
I use Malwarebytes with Windows Defender. Just make sure in the Malwarebytes menu/control page, under Settings, scroll down to Windows Action Center and tick "Never register Malwarebytes in the Windows Action Center. Otherwise, Windows Defender will disable itself.
