I had this problem , try unplugging everything attached to your sp including your micro sd card, than if any other updates are cued up uncheck them and run each one at a time. After I was done and it went thru than i did this, ((Try opening a command prompt window as an administrator and running
sfc /scannow (disclosure cut, copied from someone in another thread, but this is supposed to clear out issues left behind,)) i also read if your update did not go through than run this and retry the update with everything unplugged.
I have noticed that as far as Windows Updates are concerned you must NEVER do a "Search for updates" before installing. Just set it to automatically install updates and ONLY install the ones they suggest when they suggest them.
In case you have Office on your computer you can still "Search for updates" on those but install ONLY the Office updates.
I have been using this and it works like a champ there is a way to set it to auto update the Windows defender. Search for it. It has been a while since I set it up. I think it is as administrator. Windows Update Notifier Free Download. It will give you a notification when updates are available. Or letyou know after the defender ones are updated.