Unable to start Windows defender - error 577

I recently (my fault) suffered a major malware attack. I removed the installed programs and ran malwarebytes which removed a great deal more junk. I then went to run a windows defender scan and got the following message.

This App is turned off by Group Policy ..  to allow this app to run

contact administrator to enable the program via group policy.              NOTE   I am sole user & administrator 2yr old Dell desktop using 8.1

I went to computer management , selected Windows Defender Service and clicked start. The app tries to start showing a progress bar, but fails to do so and I get the following message.

Windows could not start Windows Defender Service on local computer

Error 577 windows cannot verify the digital signature for this file. A recent hardware or software change might have install a file that is signed incorrectly or damaged or that might be malicious software from an unknown source.

I ran malwarebytes again with no affect. Then I downloaded the free version of AVG security software and scanned the system with it. AVG removed more malware and is running and protecting my pc. But did not restore Windows Defender. It also appears that windows auto update is not working.

I have tried to restore back to prior to the malware event but pc fails to restore to that point the next point available would take my pc way too far back.

Note my PC is currently preforming correct with no other issues or problems.

Original Title: mhscott16

Moved from Windows

Answer
Answer
Thank you for your input I am sure some will find it helpful. In my case Defender was corrupted by a severe malware attack that I accidentally opened the door to. I download the 3rd party security software to see if it could find something. Which it did and removed the malware along with another malware tool.  I then uninstalled both software. Defender was still corrupted and would not start even with repeating previous solutions mentioned above. Somehow the malware attacked damaged defender.  I had tried a restart that failed. I ended up take my computer further back to a restore point several months ago when I added a new external hard drive. This worked Defender was restored. 

Was this reply helpful?

Sorry this didn't help.

Great! Thanks for your feedback.

How satisfied are you with this reply?

Thanks for your feedback, it helps us improve the site.

How satisfied are you with this reply?

Thanks for your feedback.

 
 

Question Info


Last updated February 11, 2024 Views 7,541 Applies to: