Using a firewall is like locking the front door to your house—it helps keep intruders (in this case, hackers and malicious software) from getting in. Windows Firewall is included in Windows and is turned on by default.

If you see a warning that your firewall is turned off, it could be because:

  • You or someone else has turned off your firewall.
  • You or someone else has installed antivirus software that includes a firewall and that disables Windows Firewall.
  • The warnings that you see are fake alerts, caused by malicious software.

You do not need to turn off your firewall

There are two ways to allow an app or a program through a firewall. Both are risky, but not as risky as turning off your firewall. Learn how to allow an app through a firewall in Windows 8 or Windows 7.

Check your firewall settings in Windows 8

If you think your firewall is turned off, open Windows Firewall by swiping in from the right edge of the screen, tapping Search (or if you’re using a mouse, pointing to the upper-right corner of the screen, moving the mouse pointer down, and then clicking Search). Type firewall in the search box, tap or click Settings, and then tap or click Windows Firewall.

In the left pane, tap or click Turn Windows Firewall on or off . You might be asked for an admin password or to confirm your choice.

For more information, see Windows Firewall from start to finish.

Check your firewall settings in Windows 7 and Windows Vista

If you think your firewall is turned off, follow these steps:

  1. Open Windows Firewall by clicking the Start button , and then clicking Control Panel. In the search box, type firewall, and then click Windows Firewall.
  2. In the left pane, click Turn Windows Firewall on or off.  If you’re prompted for an administrator password or confirmation, type the password or provide confirmation.
  3. Below each network location type, click Turn on Windows Firewall, and then click OK. We recommend that you turn on the firewall for all network location types.

You don’t need antivirus software that includes a firewall

Because Windows comes with a firewall, you don’t need to install an additional one. You don’t need to buy or download antivirus software that includes a firewall.

Windows 8 also comes with built-in antivirus software that is turned on by default, so you do not need to install other antivirus software.

If your computer is running Windows 7, Windows Vista, or Windows XP, you may want to install antivirus software to help protect your computer. You can install Microsoft Security Essentials for free. If you’ve already installed other antivirus software, you will need to uninstall the other antivirus software before you install Microsoft Security Essentials.

Microsoft Security Essentials includes integration with Windows Firewall, so you can turn Windows Firewall on by using Microsoft Security Essentials.

Watch out for fake alerts

Rogue security software is malicious software that might display fake warnings telling you that your firewall is turned off, even if it isn’t. If you think your computer is infected with rogue secure software, use your antivirus software or do a free scan with the Microsoft Safety Scanner. For more information, read Watch out for fake virus alerts.