Find and Use the Windows 10 Firewall

Protect your computer while controlling application access to the internet

Network security, conceptual artwork
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All Windows computers include features that protect the operating system from hackers, viruses, and various types of malware. One of them, Windows Defender Firewall, has always been a part of Windows and was included with XP, 7, 8, 8.1, and more recently, Windows 10. It’s enabled by default. Its job is to protect the computer, your data, and even your identity and runs in the background all the time

Why Are Firewalls Important?

In the physical world, a firewall is a wall designed specifically to stop or prevent the spread of existing or approaching flames. When a threatening fire reaches the firewall, the wall maintains its ground and protects what’s behind it.

Windows Defender does the same thing, except with data — or more specifically, data packets. One of its jobs is to look at what’s trying to come into and pass out of the computer from websites and email, and decide if that data is dangerous or not. If it deems the data acceptable, it lets it pass. Data that could be a threat to the stability of the computer or the information on it is denied. It is a line of defense, just as a physical firewall is. This, however, is a very simplistic explanation of a very technical subject. If you’d like to dive deeper into it, this article “What is a Firewall and How Does a Firewall Work?” shares more information.

Why and How to Access Firewall Options

Windows Defender Firewall offers several settings that you can configure:

  • Manually block a program that’s allowed by default, such as Microsoft Tips or Get Office. When you block these programs you, in essence, disable them. If you’re not a fan of the reminders you get to buy Microsoft Office, or if the tips are distracting, you can make them disappear.
  • Opt to let apps pass data through your computer that aren’t permitted by default. This customization often occurs with non-native apps you install like iTunes because Windows requires your permission to allow both installation and passage. But, the features can also be Windows-related such as the option to use Hyper-V to create virtual machines or Remote Desktop to access your computer remotely. 
  • Turn off the firewall completely. Do this if you opt to use a different vendor's security suite, like the anti-virus programs offered by McAfee or Norton. These frequently ship as a free trial on new PCs and users often sign up. You should also disable the Windows Firewall if you’ve installed an alternative.

Don’t disable the Windows Defender Firewall unless you have another in place, and don't run several firewalls at the same time.

Change Windows Firewall Settings

When you’re ready to make changes to Windows Firewall, type Windows Defender in the Search area of the Taskbar then select Windows Defender Settings from the list.

From the Windows Defender Firewall area, you can do several things. The option to Turn Windows Firewall On or Off is in the left pane. It’s a good idea to check here every now and then to see if the firewall is indeed enabled. Some malware, should it get by the firewall, can turn it off without your knowledge. Simply click to verify and then use the back arrow to return to the main firewall screen. You can also restore the defaults if you’ve changed them. The option Restore Defaults, again in the left pane, offers access to these settings.

Settings marked with a blue-and-gold shield require an administrator-level password to access.

How to Allow an App Through the Windows Defender Firewall

When you allow an app in Windows Defender Firewall you choose to allow it to pass data through your computer based on whether you’re connected to a private network or a public one, or both. If you select only Private for the allow option, you can use the app or feature when connected to a private network, such as one in your home or office. If you choose Public, you can access the app while connected to a public network, such as a network in a coffee shop or hotel. As you’ll see here, you can also choose both.

To allow an app through the Windows Firewall:

  1. Click Allow an App or Feature Through Windows Defender Firewall.
  2. Click Change Settings and type an administrator password if prompted.
  3. Locate the app to allow. It won’t have a check mark beside it.
  4. Click the checkbox(es) to allow the entry. There are two options Private and Public. Start with Private only and select Public later if you don’t get the results you want.
  5. Click OK.

How to Block a Program with the Windows Defender Firewall

The Windows Firewall allows some Windows 10 apps and features to pass data into and out of a computer without any user input or configuration. These include Microsoft Edge and Microsoft Photos, and necessary features like Core Networking and Windows Defender Security Center. Other Microsoft apps like Cortana might require you to give your explicit permissions when you first use them, though. This approval opens the required ports in the firewall, among other things. You can withdraw your consent to bypass the firewall, however.

To block a program on a Windows 10 computer:

  1. Within the Windows Defender Firewall applet, click Allow and App or Feature Through Windows Defender Firewall.
  2. Click Change Settings and type an administrator password if prompted.
  3. Locate the app to block. It will have a check mark beside it.
  4. Click the checkbox(es) to disallow the entry. There are two options — Private and Public. Select both.
  5. Click OK.

After you’ve completed this process, the apps you’ve selected are blocked based on the network types you’ve selected.

To manage the Windows 7 Firewall, refer to the article “Finding and Using the Windows 7 Firewall”.