Some of the nerds at my job are doing this:
- go to the start menu
- search "services"
- search for "Windows Update" in the Services window
- right click on Windows Update" and select "stop"
- open up a file explorer window and go to "C:\Windows\SoftwareDistribution"
- delete everything in that folder
- go back to the "services" window
- right click on "Windows Update" again and click on "Start"
- Reboot your computer
- try windows update again.
I guess this is an old fix from windows 7 days..? good luck!