I have experienced the same error trying to upgrade to Windows 10 Version 1607 on my HP Probook 4540s. After spending several hours on the phone with MS Support and trying to install upgrade by various methods, the tech support person said the problem was due to the fact I had the physical disk partitioned into two or more logical drives. He said the only solution was to restore the drive to a single partition and reinstall Windows 10 from scratch.

What a bunch of baloney! Why is this MY problem? Why doesn't MS fix the upgrade process so it supports multiple partitions? But that might mean they would have to admit an error. I don't know why I expected more from MicroSquish!