A firewall is a piece of software or hardware that helps keep out hackers, viruses, and worms that try to reach your computer over the Internet. Whether you are a residential or small-business user, using a firewall is the most effective first step you can take to help protect your device. It is important to turn on your firewall and antivirus software for all devices that are connected to the cable modem or wireless router.

To check or modify Windows firewall settings, follow the instructions below for your version of the Windows operating system:

Windows 10:

Windows 10 includes an integrated robust firewall solution called Windows Defender Firewall.  It is important to have Microsoft Defender Firewall on, even if you already have another firewall on. It helps protect your computing device from unauthorized access.

To turn Microsoft Defender Firewall on or off:

1. Select the Start button > Settings > Update & Security  > Windows Security and then Firewall & network protection. Open Windows Security settings
2. Select a network profile.
3. Under Microsoft Defender Firewall, switch the setting to On. If your device is connected to a network, network policy settings might prevent you from completing these steps. For more info, contact your administrator.
4. To turn it off, switch the setting to Off. Turning off Windows Defender Firewall could make your device (and network if you have one) more vulnerable to unauthorized access. If there is an app you need to use that's being blocked, you can allow it through the firewall, instead of turning the firewall off.

Note: If you get errors, or if the setting won't turn on, you can use the troubleshooter and then try again.