Recently, many customers reported the Windows Firewall issue. This seemed to be caused by a wide spread malicious application.
The error message "Windows Firewall can't change some of your settings. Error code 0x80070424" will pop up when you try to change the Windows Firewall settings. In the meantime, when you restart the system, it might pop up an error saying that "Base Filtering Engine Service" could not be found in the system.
Please note that the same error code could pop up when you try doing anything in Windows Defender.
Download the registry files (You can also export HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\BFE from another working Win7 PC)
Launch and import them to registry
Restart your PC
Now,open RUN and type
regedit and click ok
go to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\BFE
Right click on it-permissions
Click on ADD and type
Everyone and click ok
Now Click on Everyone
Below you have permission for users
Select full control and click ok
Now,open RUN and type services.msc and click ok
start base filtering engine service and then windows firewall service
Note:Modifying REGISTRY settings incorrectly can cause serious problems that may prevent your computer from booting properly. Microsoft cannot guarantee that any problems resulting from the configuring of REGISTRY settings can be solved. Modifications of these settings are at your own risk...