Fix Windows Defender Firewall not open on Windows 10 (2020 Tips)

Here’s how to Fix Windows Defender Firewall not open on Windows 10. Learn more?

* 5 Best Free Firewall Software for Windows 10 of 2020
* Fix A firewall is blocking file sharing between Windows & the containers in Docker
* Open a Port on Windows Defender Firewall in Windows 10/8/7/XP SP3