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:
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.
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.
If you think your firewall is turned off, follow these steps:
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.
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.
That's fine for 7 & 8, but what about some of us that still use XP?
I agree with Ken, I am still running XP
When I power up my PC, a balloon pops up saying 'my computer is at risk'; I click on the balloon and the Security Center window says everything is ON.
don't know if i have firewall .....would like to have it on
@Ken & simon
Windows XP has firewall as well. It should be on. If not, most likely you have a virus that disabled it.
Most likely you have a virus:
Use F-secure to scan your system if you have Windows 7 and under:
@ janet pouliot
It should be on. Check your control panel and see if it is on. If not, say what system your using and will try to help you.