Windows Defender Antivirus in Windows 10 Creators Update
includes always-on protection which consists of real-time protection, behavior monitoring and heuristics to identify and block malware based on known suspicious and malicious activity.
Comparison of settings and functions of the old app and the new app
All of the previous functions and settings from the Windows Defender app (in versions of Windows 10 before version 1703) are now found in the new Windows Defender Security Center app. Settings that were previously located in Windows Settings under Update & security > Windows Defender are also now in the new app.
That would include Windows 10 Anniversary update
's Limited Periodic Scanning
which provides additional protection against malware for those using a third party anti-virus program as their primary protection. This feature allows you to run occasional scans with Windows Defender without conflicting with a third-party anti-virus. When enabled, Windows 10 will use the Windows Defender scanning engine to periodically scan your computer (or allow you to schedule scans) for threats and remove them.
Windows Defender should not have blocked Comodo Antivirus (Internet Security). When unexpected issues arise with anti-virus software, I generally recommend a reinstall which resolves most problems...unless the product offers a "Repair
" option which you can try first.