Windows Firewall service is missing in Windows 7
You receive a message from the Action Center that the Windows Firewall is turned off. When you attempt to turn it on, you receive a message like this:
Windows Firewall can’t change some of your settings
Error code 0×80070424
Go into Services by typing services into the search bar in the start meny. You will find that the Windows Firewall service is missing. Also if you check instid the registry editor the following registry key will be missing as well:
This problem is usually caused by a virus make sure you have checked for viruses and removed all viruses as well before fixing this issue.
Copy the missing registry key from a working Windows 7 computer.You can also download this reg file and double-click it to import the missing key into your PC’s registry.
Now reboot your computer and the Windows Firewall service should be started.
If the service still won’t start, you may have permission problems or you may have other missing services such as the Base Filtering Engine
Download farbar and run it. Farbar is a network troubleshooter to fix service related issues in Windows.
Then reboot and all should be well again