Chris
Was it offered to you by Windows Update or did you go seeking it? It relates to Remote Desktop. Why did you think you needed it?
If you failed to download it I do not see how this has any bearing on your problem of System File Checker not be able to fix corrupted files. That is far more important than not being able to install an update that you may not need.
It was offered as an "important" update on Windows Update. I know cos I've been watching this thread in the hope of a clue as to why it won't install on my system.