Win 10 Pro 64 1809 to 1903 update stuck in endless install loop

Put the 'defective' 970 Pro in (disconnected 850 Evo) and did a clean install from DVD of 1809. In reboot stage that gave a CRITICAL PROCESS DIED error, rebooted a few times and same. So disconnected everything except DVD, kb & mouse. Yes the 840Pro and HGST 4Tb too. Now it went through to install and upgraded fine to 1903. So I have a clean cooked current version 'to go', may yet be using it!

So pulled out the 970 and plugged the 850 Evo and the HGST (because of the relocated Documents etc folder) and had a crack at upgrade. Failed without error again so ran back round and uninstalled Samsung Magician Rapid Drive (which was for the 840 Pro, drive O:). Pretty sure I had it cracked but no, same dang result!

The next 'being stubborn' option is to properly relocate the folders on the mech drive back to the 850 (without moving the files) and pull the mech drive out too, then I have an apples with apples situation for what just worked. Need to do other stuff now, but will get back to that... darn. So close, yet so far...

Just for completeness, this is now solved. Not by the usual reinstallation of Windows but actually cracking the problem. Turns out something about the controller on that mech drive was causing behaviours that underpinned this problem, as was the way I had transferred the operating system to the ssd in the first place. It was the second one that I solved and that got me a working solution, documented in detail here: https://answers.microsoft.com/en-us/...d-a5ada6fbd6d4. However, soon after that I isolated the HDD behaviour as it froze and green-screened on me. Then I relised what I had observed earlier but not seen was this same behavior.

The HDD was a 2yo HGST 4TB Deskstar. It passed all tests but sometimes took an extremely long time to copy files, hours where minutes was more appropriate for file size and qty.

I don't know now which was the true cause, but just adding this comment should some other tormented soul find their way here due to a parallel experience; hopefully this will be the key to unlocking the misery and getting back to peace and good karma :).

Glad to read that it's sorted.

do realize that the 1903 version goes out of support this December 2020 (no more 1903 updates after that)

time to update to 1909 or higher