This guide targets two separate but intertwined groups: Those who have recently upgraded from Win7 (or, less likely, Win8.1) and those who have upgraded from an earlier version of Win10 (likely the November Update, Version 1511) to a recent version (as of this writing, probably the Anniversary Update, Version 1607). [See the full post at: Windows 10 upgrade problems – and what to do about them]
Gunter Born has an interesting revelation about error 0xC0020012 on his Born City web site.