I have been having issues with Windows 10's cumulative updates failing for a couple of weeks now. I've tried running SFC /scannow, I've tried running using DISM to replace corrupted system files, I've tried downloading the update and running it manually, I've tried running an in-place upgrade (Windows 10 Pro x64 to Windows 10 x64 upgrade, so wouldn't lose programs or settings) (which failed, by the way), and I don't even remember what all else I've tried, all to no avail. There doesn't appear to be an answer to my specific problem anywhere on the internet.
My computer is running Windows 10 Pro 64-bit.
I am also running a solid-state drive (system drive) and a hard drive. I've got the folders inside C:\Users linked to a location on the HDD with directory junctions to save space on the SSD.