Noticed today there is a KB3189866 update stuck at 45% for a few hours, and I have tried everything to get it going.
Tried the Windows update Trouble shooter, and it found no issues,
as well as , check if the Windows update service is running. Refer to these steps:
- Press Windows key +R, type services.msc
- Locate the Windows update service and check if it is running.
- Double click on the service, click on Stop and Start the service again, also check if the Startup type is set to Automatic.
including the script on this page, which basically resets windows update :