I was unable to run an elevated command prompt. I was unable to do anything, except make a copy of my important files, and make a list of my installed programs. (Because I couldn't run task...

Well, I have the same problem - but, I'm logged in as "Dan":

C:\Users\Dan>net localgroup administrators
Alias name administrators
Comment Administrators have complete and unrestricted...

It was an interesting thought - that the reason access was denied to my C: drive was because it was in AHCI mode. I changed it; still, access denied.

I'll try Digiwiz MiniPE when I have access to...

Sure, I can hang around for a day or two - it will take me that long to catalog my programs and copy off my data. The good news is, I have an operational system, I just can't do anything that...

No matter what I do, I can't gain administrative privileges for my W10 PC:

Never prompted to elevate privilege as administrator - Windows 10 Forums

I never reset my administrative password when...

OK, I tried Dinesh's tutorial. First, here's a list of accounts for my machine:

49681

I held down Shift and rebooted, and got the WinRE splash screen. I was prompted to log in, with "Dan" my...

This sounds promising - I will give it a try this weekend, when I have time. I admit to being confused, though - is "administrator" in the reference you cite:

net user administrator /active:yes
...

I am logged into the "Dan" user account, non-administrative. From this account, I want to "Run As Administrator". Normally, I would be prompted for the administrator password. Now, I'm not.
...

I recently upgraded my W8.1 system to W10. I'm assuming my administrator password is the same as it was - I don't recall being prompted to change and save it - but, I'm never prompted for it. ...