Windows Firewall Troubleshooter is the official Firewall troubleshooter from Microsoft.

While most troubleshooters can be found as part of Windows, techs and end users always find it easier to have the official app.

Windows Firewall Troubleshooter is a diagcab file, meaning all you need to do is double-click it like any executable. You will then be taken through step-by-step as the app looks for problems. If a problem is found, it will be explained, and you can choose to repair or exit.

Windows Firewall Troubleshooter is easy enough for anyone to use and a good place to start if you're having firewall issues.