Using DISM to repair WIndows when sfc /scannow can't repair Windows 10

I have found that sfc /scannow doesn't repair system files on Windows 10 in many cases.  Sfc /scannow will find problems but not repair them.

I have found a fix that won't work for the average user - only sysadmins with access to a Windows 10 ISO.

Here's what I did:

• Downloaded the Windows 10 Pro 64 bit version 1511 ISO from "Microsoft Volume Licensing Service Center" - this 4 GB file will take a while to download
• Mounted the ISO file as d:
• Ran this command from an elevated command prompt:
  DISM /Online /Cleanup-Image /RestoreHealth /source:WIM:d:\Sources\Install.wim:1 /LimitAccess
• Re-ran "sfc /scannow" after the DISM command above finishes