Taming Windows Defender - How To Allow Unrecognized Apps On My PC

For many years, I have used Rainlendar-Lite as a desktop calendar app with Windows. Recently they advised me of a new version being available, so I downloaded the installer and tried to run it, first the normal way and then with Administrator privileges. In every case, Windows Defender blocks the executable because it doesn't recognize the publisher.

I scanned the install program with Webroot SecureAnywhere v 9.0 and it found no problem. I noticed that Windows Defender is using Public Network settings on my computer, which is NOT connected to a public network, but the settings look exactly the same.

Previously, Windows gave me the option to take responsibility for running unrecognized apps on my system, but apparently that option has been taken away. What is the best way to regain control over my system?

Windows Version 1909 Build 18363.592

I finally got some help from a MS technical support assistant. Apparently my system had a spasm and turned "on" some security settings that were causing my problem. Here's what worked for me:

1. Start the Windows Security app
2. Choose App & Browser Control on the left panel
3. Set radio buttons to "Warn" if it says "Block"

That should give you the option to install trusted software that's not on the MS list of approved apps. I often scan stuff before installing anyhow.

BTW, I'm an amateur at this so your results may differ.