Hello,
Windows Update Cleanup will only run with administrator rights, so be sure to check on that if you haven't.
You may try manually cleaning it up. Here are the steps:
- Type Services.msc on the Cortana search bar.
- Scroll down to Windows Update, right click and select Stop.
- Launch the File Explorer.
- Go to This PC > Local Disc (C:) > Windows > SoftwareDistribution.
- Rename SoftwareDistribution folder to SoftwareDistribution_1.
- Restart your PC.
Once booted up, go back to the Windows folder. You will notice that there will be two Software Distribution folder. Delete the SoftwareDistribution_1 folder. This will let you clear out the Update Folder.
The softwareDistribution folder is where Windows stores temporary installation files needed to update your computer’s operating system. Deleting or moving contents of the folder can fix Windows Update issues.
Reference: Disk cleanup don't cleans Windows Update Cleanup. - Microsoft Community
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