"No valid Windows installed"

#1
Purchased, downloaded, installed "windows 10 recovery disk". Using neo tool, burned bootable USB. Booted, ran. Neither "C" drive (active Windows) nor "A" drive (clone of C) is considered by ERE as a valid installation. Huh?
I noticed after purchase that the Win10 version of ERE repairs thru "Windows 10 October 2018 Update (1809)". Am I SOL because I'm running 1903?
Thanks.

Correction: the laptop I'm trying to fix is 1803, not 1903. Also, I'm moving this to Recovery Disks, the correct thread