Base Filtering Engine cannot enable (Error 5); known remedies fail.

If I attempt to run the Base Filtering Engine, whether through an elevated command line or through services.msc run as an administrator, I receive the error:

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

This error has been encountered many years ago on this forum: my command prompt results are identical to those given there, except that I read HKEY_USERS\S-1-5-21-3794051443-449633142-1189025595-1001 for HKEY_USERS\S-1-5-21-216155784-1160685422-2861209106-1000, and likewise for HKEY_USERS ... -1000_Classes. (My research suggests this is probably just a unique identifier that varies normally for every computer.) I have provided my event logs, prepared as discussed there, for review. (Discord was necessary as the compressed file exceeded the four-megabyte limit.) Other methods proposed on this and Microsoft's official forum likewise fail. I cannot modify the registry as suggested here to grant Everyone full control: attempting yields the following error on selecting OK or even Apply:

Unable to save permission changes on BFE.
Access is denied.

Creating and importing the manual registry repair given here and recommended elsewhere on this forum reads the following error on attempting to merge:

Cannot import C:\Users\Owner\Documents\Repair.reg: Not all data written successfully to the registry. Some keys are open by the system or other processes.

Disabling Avast temporarily to enable the BFE as an administrator is ineffective. Roundabout methods, as accessing the hidden Administrator account, produce identical results to using my normal account, which is Owner and should, according to the Registry's permission, give me full control. More exotic methods as a batch file disabling and re-enabling network-related services, also from the Microsoft forum, also accomplished nothing. Scans by Avast and Malwarebytes indicate that there is no malware involved.

Because my attempts at research, and the various solutions proposed there, have come to nought, I would like to request advice from you. As I currently travel, my responses may be delayed, but I would be grateful for any advice that you can give in restoring the BFE, and with its, Windows' built-in firewall. Please let me know what you would suggest next!

I don't know how to fix your problem but, since no one else has responded, you might take a look at this-

How to Repair Base Filtering Engine Service Startup Problems?

since it seems to address some of the problems you encountered while trying to do the repairs.

TheRealMaestro said:

Other methods proposed on this and Microsoft's official forum likewise fail. I cannot modify the registry as suggested here to grant Everyone full control: attempting yields the following error on selecting OK or even Apply: Creating and importing the manual registry repair given here and recommended elsewhere on this forum reads the following error on attempting to merge:

I notice that thread that you quoted has not been ticked as the right answer. It could just be that it does not work at all.

Try the suggestion by @wither 2, as I have seen that method mentioned elsewhere on the net.

Hey I do not know much about but I would try that website from @wither 2

Attempting to merge the provided registry entry that @wither-2 had provided yields the same error message as discussed in the original post. Moreover, as described in the original post, my access is denied, despite being the Owner, in attempting to modify the permissions as detailed in that article. The security descriptor is also correct. (Indeed, I had earlier discovered that article independently and tried, without success, to implement its suggestions.) I am quite confident that my system suffers no malware infestation. At this stage, I am at a loss on what action next to take. How should I proceed?

Has this problem occurred since installing Avast, or did the problem exist before then?

iko22 said:

Has this problem occurred since installing Avast, or did the problem exist before then?

Avast has been installed onto this computer since 2015, and I have read others report that Avast will fail to install should the Base Filtering Engine malfunction; this presents circumstantial evidence that this has occurred since installing it, though I cannot know even roughly when. (I had only noticed that it was disabled when looking through Services while helping a friend with the recent issue with Adobe Update: in my list I saw that the Base Filtering Engine, while set to start automatically, was not running and could not be made to run.)

Yes, good thinking. Only I had seen reports of people running into this problem after failing to remove their old Anti-Virus properly, using the appropriate anti-virus removal tool. Therefore could it be that the computer was new to you in 2015, or has the computer had a different anti-virus, prior to 2015, prior to installing the Avast? If it is the case that you have had a different anti-virus product prior to Avast, then you may need to go back and remove remnants of their product, using their anti-virus removal tool.