Were you one of those who installed the server 2012 binaries into your Windows 8.1 to enable Disk Deduplication? Did you turn on dedupe on all of your drives, saving hundreds of gigs of storage space, then upgrade to Windows 10?
Upon boot, were you greeted with frequent ‘the machine cannot access the file’ errors? If so, then this is the guide for you!
This fixes the error 0x80070780: The file cannot be accessed by the system
What happened to my stuff? Did I lose it all?
NO! You did not lose your files. What happened when you ran deduplication on your files, is that Windows gradually scrubbed all of the common elements out of many files in order to compress them, much like what happens when you put files into a .zip or .rar archive.