[fChk]

As far as I'm aware installing any other antivirus product will disable the Windows Defender Antivirus component to prevent conflicts. Every well known and average (Avast, AVG, Avira and etc) antivirus should be enough. Not sure about obscure products like Dr. Web or some Chinese stuff. Rather stay away from those anyway.

Windows Defender will automatically turn off when a user installs a third-party solution. And when the user uninstalls it again, Windows Defender will turn back on again automatically. It's a core system feature not a the third-party capability.

Microsoft has always allowed power users to disable M$ defender via the system's registry by enabling(/or disabling in the reverse case) an entry called 'DisableAntiSpyware'. Once this option is set with value '1', the system turns off Windows Defender.

With Win 10 latest version that no longer applies except for Windows Servers. Read this M$ doc for more:
https://docs.microsoft.com/en-au/windows...ntispyware

A side note though!.. Why would anyone want to disable M$ defender ?!!.. Native solutions are always the best whatever stuff third-parties vendors will tell you to convice you otherwise.

A system should always be lean and mean. Third-party solutions can have more options, best configs but always bloated.. So be Smart!..