(1)
(a) When you switch on your computer & sign in - it should be to your user account. The Administrator account is for emergencies (& probably should be shut off until then). It is good you haven't been initiating the 1909 upgrade in the Administrator account.
I don't think it is amenable to it.
(b) You change those drive letters in the internal recovery environment (Shift+Restart). That's where they are messed up. When you enter the Command Prompt there, you are asked to select a user & then for the password. I think you said both
the Administrator & your user account allowed you in. So - use the user account. If it fails, use the other. That would be an emergency.
(2) That's right. When you "copy", it goes into the Clipboard. When you "paste", it comes out. But the Clipboard is cleared when Windows boots. It might not even be the same Clipboard for all I know. So, you can't use it to get text from the recovery environment
into Windows.
However, in the recovery environment, you can paste into a file. Then, after booting back to Windows, get it out of the file. Let us practice using a file here in Windows...
(a) Open an Administrator Command Prompt.
(b) Enter the following commands...
NET USERS
NET USER Administrator
NET User <your user name>
---- Use Ctrl-A & Ctrl-C to copy it ----
Notepad
Then use the File menu to Save AS. Browse to a folder of your choice, put a name into the name box (keep the .txt file type), & save it. If you were in the recovery environment, the file still is there after you boot back
to Windows. Here is the contents of mine...
Microsoft Windows [Version 10.0.18363.815]
(c) 2019 Microsoft Corporation. All rights reserved.
C:\WINDOWS\system32>net users
User accounts for \PCRSCOMPUTER
Administrator DefaultAccount Guest
My_User_Name WDAGUtilityAccount
The command completed successfully.
C:\WINDOWS\system32>net user administrator
User name Administrator
Full Name
Comment Built-in account for administering the computer/domain
<<< See?
User's comment
Country/region code 000 (System Default)
Account active No
<<< And mine is inactive - OFF
Account expires Never
Password last set 8/8/2018 10:09:17 PM
Password expires Never
Password changeable 8/8/2018 10:09:17 PM
Password required Yes
User may change password Yes
Workstations allowed All
Logon script
User profile
Home directory
Last logon 8/8/2018 10:10:05 PM
Logon hours allowed All
Local Group Memberships *Administrators
Global Group memberships *None
The command completed successfully.
C:\WINDOWS\system32>net user My_User_Name
User name My_User_Name
Full Name PCR Just PCR
Comment
User's comment
Country/region code 000 (System Default)
Account active Yes
Account expires Never
Password last set 4/20/2019 6:20:00 PM
Password expires Never
Password changeable 4/20/2019 6:20:00 PM
Password required Yes
User may change password Yes
Workstations allowed All
Logon script
User profile
Home directory
Last logon Never
Logon hours allowed All
Local Group Memberships *Administrators <<< Does yours say "Administrators"?
Global Group memberships *None If so, it is an Administrator
The command completed successfully.
C:\WINDOWS\system32>notepad
C:\WINDOWS\system32>