1. Select the “Start” button, then type “firewall“.
2. Select the “Windows Defender Firewall” option.
3. Choose the “Allow an app or feature through Windows Defender Firewall” option in the left pane.

4. Unchecking the box to the left of the application name disallows it from accessing network resources, while checking it allows 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.

5. If the program you wish to block or unblock is not listed, you can click the “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.