How to Fix Base Filtering Engine Service Startup Problems

The Base Filtering Engine (BFE) service is a crucial network component targeted by many malware. If the BFE service doesn’t start, many services, such as Windows Firewall, Routing, Remote Access, and others, fail to start.

Should the BFE service be missing from the Services MMC, or if the Action Center warns you that the Windows Firewall isn’t enabled, it’s highly likely that your system is under attack. Have it checked thoroughly using a reputed anti-malware tool, or you may seek professional help to eliminate malware. Trying to repair these services when malware is on board your system isn’t going to help in most cases.

This post assumes that you’ve done a malware cleanup and looking for information on how to fix the services such as BFE, Windows Firewall, and others.

The first (and probably the only) thing most of us do to reinstate the Base Filtering Engine Service is to import the service registry keys from a similar computer, which is a correct step. But this only enlists the service in the Services MMC, but the required service Permissions aren’t assigned automatically. Due to missing special permissions for the BFE service, the following errors occur when you try to turn on the BFE or Windows Firewall.

Some of the error messages you may see:

Action Center can’t turn on Windows Firewall

Turning it on via the Windows Firewall applet may show up an error saying Windows Firewall can’t change some of your settings. Error code 0x80070433 or 0x8007042c.

Services MMC: Windows could not start the Windows Firewall service on Local Computer. Error 1075: The dependency service does not exist or has been marked for deletion.

Services MMC: Windows could not start the Base Filtering Engine service on Local Computer. Error 5: Access is denied.

This is recorded in the System event log as well:

Log Name: System
Source: Service Control Manager
Date: 1/9/2020 8:21:25 AM
Event ID: 7023
Task Category: None
Level: Error
Keywords: Classic
User: N/A
Computer: W10-PC
Description:
The BFE service terminated with the following error:
Access is denied.

Resolution: Repair Base Filtering Engine Service

Step 1: Fix the BFE Service Registry Keys

First, create a Restore Point, and then restore the BFE service registry entries by downloading the appropriate .zip for your version of Windows:

BFE for Windows 7 | BFE for Windows 8 | BFE for Windows 10 | BFE for Windows 11

Unzip and run the enclosed .reg file. This registers the BFE service back.

Step 2: Fix the BFE registry permissions

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\BFE

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\BFE\Parameters\Policy

The next step is to fix the BFE service permissions.

1. Start regedit.exe and go to the following registry path:

   HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\BFE\Parameters\Policy

2. Right-click Policy, and click Permissions
   
   It has some default permissions inherited from the parent key. By default, the SYSTEM and Administrators groups have full control permission. But this isn’t enough to start BFE.
   
3. Click on the Add button.
   
4. In the Enter the object names to select: box, type NT SERVICE\BFE, and click OK.
   
5. BFE is added to the list of Group or user names. We need to give it special permissions. Click Advanced
   
   
6. Select BFE, and click the Edit button.
   
7. In the Permission Entry dialog, enable or Allow the following Permissions for BFE:
   • Query Value
   • Set Value
   • Create Subkey
   • Enumerate Subkeys
   • Notify
   • Read Control (this is added by default when you added BFE)
8. After adding the above (six) Permissions, click OK.
   
9. You’ll be back at the Advanced Security Settings dialog now. Select BFE, click Replace all child object permissions with inheritable permissions from this object, and click OK.
   
10. You’ll be back at the standard permissions dialog. Simply click OK and close the dialog.
    
11. Restart Windows, and then launch the Services MMC (services.msc)
12. Double-click Base Filtering Engine and check its status. If the permissions are correct and no malware is on-board, the Base Filtering Engine service should show the status Started.
    

Step 3: Check the Security Descriptors

Still no dice..? If the above steps fail to resolve the issue, resetting the BFE service permissions or security descriptors should do the trick.

1. Open an elevated or admin Command Prompt.
2. Type in the following command:

   [Windows 7 and Windows 8]
   SC SDSET BFE D:(A;;CCLCSWRPWPDTLOCRRC;;;SY)(A;;CCDCLCSWRPWPDTLOCRSDRCWDWO;;;BA)(A;;CCLCSWLOCRRC;;;IU)(A;;CCLCSWLOCRRC;;;SU)
   
   [Windows 10]
   SC SDSET BFE D:(A;;CCLCLORC;;;AU)(A;;CCDCLCSWRPLORCWDWO;;;SY)(A;;CCLCSWRPLORCWDWO;;;BA)(A;;CCLCLO;;;BU)S:(AU;FA;CCDCLCSWRPWPDTLOSDRCWDWO;;;WD)
   
   [Windows 11]
   SC SDSET BFE D:(A;;CCLCLORC;;;AU)(A;;CCDCLCSWRPLORCWDWO;;;SY)(A;;CCLCSWRPLORCWDWO;;;BA)(A;;CCLCLO;;;BU)

   Make sure there are no spaces in the Security Descriptor string. It should be like this:
   
   SC <SPACE> SDSET <SPACE> <SECURITYDESCRIPTOR>
   
   

• Check out this article for background information on service Security Descriptors (SDDL).

And you should see the message SetServiceObjectSecurity SUCCESS. Restart Windows once again.

Instead, if you get the error SetServiceObjectSecurity FAILED 5: Access is denied, then the registry key permissions or the service permissions are wrong somewhere. In that case, re-run all the steps above in Safe Mode and verify the permission entries. It should work eventually!