sfc /scannow WILL NOT function

You are welcome. I'm benefitting from this thread as well. I've got a hugely updated AOMEI Partition Assistant now, for instance, & I found out about my own letter shenanigans in the 1909 internal recovery environment. That's where we go when we boot to the recovery partition (Shift+Restart). After we get your computer upgraded to 1909 (best outcome), I'll be very interested to know whether you, too, will see a letter added automatically to the recovery partition when viewed with DiskPart in that environment. If it becomes C:, we'll be able to fix that. I don't mind it having another letter -- although, if I had a D: partition like you -- I'd want D: to remain D: as well. Of course, it all goes away automatically after booting back to Windows. And booting to the external recovery environment (on the Win 10 Installation USB) also does not exhibit that phenomenon. That's where "Repair your computer" goes.

(1) "The USB wouldn't open in recovery - it loops repeatedly."

     "This is a list of what is on it"

That list looks fine. Currently, your internal recovery environment is 1809. Your external environment on the 1909 Installation USB is 1909. But they both go to a "Choose an Option" screen. Are you mistaking that for a loop? The 1909 one has more options. Also, it has an updated Command Prompt, DiskPart, etc. I want to see what happens to letters in each one. And when you've got an internal 1909 environment (if/when we get the upgrade to run), let us see the letters there too.

(2) "notepad has to be opened first or I just get a list of commands"

Sounds like you didn't type "Exit" to leave DiskPart. So, it gave you a list of proper DiskPart commands. You may type "Help" followed by one of those commands for usage descriptions. "Help GPT", for instance, will show you what those attributes do. Notepad isn't in DiskPart. You have to exit DiskPart, then the Command Prompt will recognize Notepad.

(3) "No, I don't sign in using administrator unless"

I would first try fixing things while signed into your account. If it fails, then resort to Administrator. Not everything done in one account will affect the others. It might be the fix will be something that has to be done in your account. (But it's time to admit I don't know much else about it.)

1. No, I don't sign in using administrator unless I'm trying to fix something and that's usually the cmd prpt (from right-click start button) There are a few programs there on the desktop, mostly Microsoft and a few of mine that I have set to "use by anybody" in their properties.
2. DRIVES (notpad has to be opened first or I just get a list of commands that can be used and what the mean like install, select, assign etc.)

Microsoft Windows [Version 10.0.17763.557]

(c) 2018 Microsoft Corporation. All rights reserved.

C:\WINDOWS\system32>notepad

C:\WINDOWS\system32>diskpart

Microsoft DiskPart version 10.0.17763.1

Copyright (C) Microsoft Corporation.

On computer: MYPC

DISKPART> list vol

  Volume ###  Ltr  Label        Fs     Type        Size     Status     Info

  ----------  ---  -----------  -----  ----------  -------  ---------  --------

  Volume 0     E                       DVD-ROM         0 B  No Media

  Volume 1         Windows RE   NTFS   Partition   1023 MB  Healthy

  Volume 2     C   Windows      NTFS   Partition    919 GB  Healthy    Boot

  Volume 3                      NTFS   Partition    492 MB  Healthy

  Volume 4     D   Recovery Im  NTFS   Partition     10 GB  Healthy

  Volume 5         SYSTEM       FAT32  Partition    360 MB  Healthy    System

  Volume 6     H   ESD-USB      FAT32  Removable     32 GB  Healthy

__________________________________________________________________________

The USB wouldn't open in recovery - it loops repeatedly. From "choose an option" > UEFI USB  > county/language window, next> clicked repair in lower left corner then it loops back to choose an option every time. I change USB ports, everything else is unplugged and tried both admin and my accounts. Same result.

This is a list of what is on it from the download - in case something is amiss.

Folders- boot, efi, sources, support

files- autorun, inf, bootmgr, bootmgr efi, and setup.exe,

Thank you again, by the way, for trying to straighten this out with me.

(1) "

Yes I have that-

Local Group Memberships      *Administrators


Global Group memberships     *None


"

I presume that is in your account (which means it's an administrator) as well as in the Administrator account. And did the latter say it was the Built-In Administrator like mine did? Then, really, it need not be active. But I'm thinking now - so long as you resort to it only in an emergency - it's OK to leave it ON. You don't sign into it & run any apps that create files -- do you? It isn't meant for that. The Built-In Administrator is only for emergency use.

But one of the worst emergencies exists when the computer has no administrator account (inadvertently deleted or just dysfunctional). It becomes impossible to troubleshoot. That is when the Built-In Administrator is meant to be used. Sadly -- I've seen threads here wherein it seems -- it takes an Administrator to turn on the Built-In Administrator. So, that's a catch 22 that suggests, maybe, it isn't really bad to leave yours turned ON. But only use it in an emergency.

(2) "The drive letters seem to be right now"

Try it once more...

(a) Plug in your 1909 Installation USB for one more letter.

(b) Shift+Restart to the 1809 internal recovery environment (that partition).

      Is C: OK at its Command Prompt? What about D:?

(c) Exit back to the Choose an Option screen, & click "Use a Device" to boot to the USB.

(d) Click "Repair your computer" for the 1909 external recovery environment.

     How are C: & D: now?