Fix windows update stuck downloading updates windows 10 | Windows101Tricks | Scoop.it
From www.howtofixwindows.com - October 13, 2017 3:31 PM

Mostly Windows update problems occur when the update storage folder (C:\Windows\SoftwareDistribution) Became corrupted, You can run windows udpate torubleshooting tool, And clear SoftwareDistribution to fix any update related problems on windows 10. http://www.howtofixwindows.com/fix-windows-update-stuck-download-install/