How to enable Windows Defender Firewall

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FirewallsHigh priority

About 5 minutes to complete

Make sure Windows Defender Firewall is turned on for both private and public networks on your Windows computer.

Step-by-step guide

Open Windows Security (search for it in the Start menu).
Click 'Firewall & network protection'.
Check that the firewall is On for Domain, Private, and Public networks.
Click any that show 'Off' and turn them on.
If an app ever asks you to turn the firewall off, don't. Instead allow just that one app through it; Windows will usually offer this when you first run the app.

5 steps

Why this matters

The software firewall on your PC adds a second layer of protection, especially when you are on a public or unfamiliar Wi-Fi network.

How to confirm it worked

The setting is saved and active on your device
You have tested it works before closing the page

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Frequently asked questions

Is Windows Defender Firewall free?

Yes. It is built into every version of Windows and costs nothing. It is managed through Windows Security, which is also free and built in.

What is the difference between Windows Defender Firewall and my router's firewall?

Your router firewall protects your entire network by blocking inbound connections from the internet. Windows Defender Firewall protects your individual computer, and it is especially useful when you connect to unfamiliar networks such as public Wi-Fi, where your router-level protection may not be in place.

Will Windows Defender Firewall block apps I want to use?

Occasionally Windows will ask whether to allow a new app through the firewall when it first tries to connect to the internet. You can choose to allow it. Most legitimate apps request this access automatically: simply decline if you were not expecting the prompt or do not recognise the application.

I use a third-party antivirus. Does it include its own firewall?

Many paid antivirus packages include a software firewall. If yours does and it is active, Windows may turn off its own firewall to avoid conflicts; this is usually fine. Check that one firewall is active: either Windows Defender or your antivirus. You should never have both disabled at the same time.

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