Windows Update No Longer Works

I have my laptop with Win 8.1 set to automatically download updates and to notify me when any are available so I can see what they are before installing them. When I realized that my almost-daily Windows Defender definition updates were not showing up, I investigated and found no check for updates had occurred since August 4th. Trying a manual check, I got an error message with a code of 80244019. Nothing I found in Windows Help or on the web has been useful.

Any ideas on how to fix this problem? Other than installing updates, I haven't made any changes whatsoever to the laptop in months.