Can I ask why Windows 10 and Windows Defender have never been updated, until both are fully up to date you are wasting your time troubleshooting and we are not in a position to help you as we have no way of knowing if you are running a legitimate version of Windows 10.
I would suggest that you get rid of Avast as it has become a bit of a monster in that it foists all sorts of unwanted extras on folk, many of which cause issues.
You can uninstall Avast in the Control Panel but should you have any problems see Avast clean removal info
here Please create a new system restore point first.
We can also see McAfee SiteAdvisor Service and other junk from Iobit on the computer, McAfee could also be causing conflict so get rid of that as well.
McAfee product removal tool (MCPR)
here
Once any other AV has been correctly uninstalled, check to see if Windows Defender has auto enabled and allow it to update and carry out a full scan of your computer.
Post back once Windows 10 and Windows Defender are both fully up to date and we will go from there if you are still having issues.
Operating System
Windows 10 Home 64-bit
Computer type: Desktop
Installation Date: 6/9/2018 10:38:14 PM
Windows Security Center
Hotfixes
Installed
Not Installed
9/14/2019 2019-09 Cumulative Update for Windows 10 Version 1803 for x64-based Systems (KB4516058)
Installation Status: Failed
Install this update to resolve issues in Windows. For a complete
listing of the issues that are included in this update, see the
associated Microsoft Knowledge Base article for more information.
After you install this item, you may have to restart your computer.
9/13/2019 2019-09 Cumulative Update for Windows 10 Version 1803 for x64-based Systems (KB4516058)
Installation Status: Failed
Install this update to resolve issues in Windows. For a complete
listing of the issues that are included in this update, see the
associated Microsoft Knowledge Base article for more information.
After you install this item, you may have to restart your computer.
9/13/2019 2019-09 Cumulative Update for Windows 10 Version 1803 for x64-based Systems (KB4516058)
Installation Status: Failed
Install this update to resolve issues in Windows. For a complete
listing of the issues that are included in this update, see the
associated Microsoft Knowledge Base article for more information.
After you install this item, you may have to restart your computer.
9/13/2019 2019-09 Cumulative Update for Windows 10 Version 1803 for x64-based Systems (KB4516058)
Installation Status: Failed
Install this update to resolve issues in Windows. For a complete
listing of the issues that are included in this update, see the
associated Microsoft Knowledge Base article for more information.
After you install this item, you may have to restart your computer