Delete Windows Update Cache

Stop wuauserv then delete or rename C:\Windows\SoftwareDistribution

Here’s a link to a powershell script.
Usual disclaimer: Use at your own risk. Check any scripts from the internet before running them.

Stop the Windows Update service (wuauserv).

stop-service wuauserv

Delete or rename C:\Windows\SoftwareDistribution

rename-item "C:\Windows\SoftwareDistribution" "C:\Windows\SoftwareDistributionOLD"

Start the Windows Update service (wuauserv). This will recreate the SoftwareDistribution directory.

start-service wuauserv

Run Windows Update to download a fresh copy of any updates.

control update