Windows 10: Windows Defender not working after rollback

As of this morning, Windows Defender is unable to function properly after rolling back from a Skip Ahead build. Here are some screens.


Real time protection is off and greyed out.






This screen shows that the version information is all blank, which isn't supposed to happen.





Upon trying to start Defender from Services, it throws this error:

"Windows could not start the Windows Defender XXX Service on Local Computer. Error 2: The system cannot find the file specified."


Steps Taken

1. I opened up the Properties for each of the Windows Defender Services. The path to the executable is "C:\ProgramData\Microsoft\Windows Defender\platform\4.18.1806.18062-0\YYY.exe", where YYY is the executable file.
   MsMpEng.exe: Antivirus Service
   NisSrv.exe: Antivirus Network Inspection Service
2. In Windows Explorer, however, the path name is "C:\ProgramData\Microsoft\Windows Defender\Platform\4.18.1807.18075-0".
3. Since the platform version numbers mismatch (4.18.1806.18602-0 and 4.18.1807.18075-0), the Error 2 pops up.

Can you please help on what is going wrong here?

:)

 

Windows Rollback - it works!


Insider Hub: Known issues

It is intentional for the 9926 release - they must be working on WinRE and it wasn't ready in time.

 

Issues with Windows defender after upgraded to Windows 10

Hi,

Thank you for posting the query on Microsoft community.

I appreciate your interest on Windows 10.

To begin with troubleshooting I would like you to answer the following question:

• How did you perform upgrade? Is it through update or through media creation tool?

I suggest you to check the latest version of Windows defender by clicking on
Settings>update and security>Windows defender.

If latest version is installed and still its not working then
I suggest you to run Windows Update Troubleshooter

Follow the below steps:

• Type troubleshooting in the search bar.
  • Select Troubleshooting.
  • Select View all on the top left corner.
  • Click on windows update.
  • Follow the on-screen instructions to run the troubleshooter.

If you have performed upgradation through media creation tool then there is no option to rollback. But if you upgrade through Windows update you can roll back by clicking on
Settings>update and security>recovery>rollback.

Please get back to us with updated status, we will be happy to assist you.

 

Windows Defender Not Working in Windows 10

Hi,

Thank you for using Windows 10.

Sorry for the delayed reply. I suggest you to Set Windows Defender to Automatic - You can set the Windows Defender service to Automatic, Disabled or Manual. Setting it to automatic might solve the problem. Follow these
steps:

• Click Start > type services in the Search box > click Services in the Programs list.
• Search for Windows defender.
• Double-click Windows Defender, and click Automatic in the start-up box > click OK.

Also, follow the below mentioned steps and check:

• Open the Task manager. Here’s a tip: Press CTRL+Shift+ESC.
• Click File > Run New Task
• Make sure you have a check mark beside “Create this task with administrative privileges”
  
• Type CMD
• Type the following 2 commands at the CMD prompt:
  
  dism /online /cleanup-image /restorehealth
  
  sfc /scannow
  
  
• Close the CMD window

Keep us posted on the status of the issue and we’ll be glad to help.