Hello ConureDelSol and welcome to Seven Forums.
Try re-setting and re-registering the Windows Update components. (See Option Two in this tutorial.) Windows Update - Reset
After doing that try installing the updates from the hidden administrator account. (See Option Two in this
tutorial.) I'd also temporarily disable your real-time AV in case it's causing a conflict. And, if you get more than, let's say, 5 updates to install, I'd do just 2 or 3 at a time. Built-in Administrator Account - Enable or Disable