With Windows Defender, you can block and unblock programs using Windows Defender Firewall for Windows 10. The process is really simple. Here's what to do:
- Press the “Start” button, then type “firewall“.
- Choose “Windows Defender Firewall”.
- Then, choose “Allow an app or feature through Windows Defender Firewall” in the left pane.
A list of application appears. There are boxes next to each app. When you uncheck the box (remove the check mark) to the left of the application name disallows it from accessing network resources.
On the other hand, checking the box grants access. You can also check the boxes to the right of the name labeled “Private” or “Public” to allow and disallow the app on private or public networks respectively.
However, sometimes, the program you want to block or unblock is not on the list. You can click on “Allow another app…” button to add it.
Choose the application in the list and select “Add". If the program is not in this list, use the “Browse…” button to select the program file manually.