Alek wrote:

The boot disk is a 5-month-old M.2 SSD. How does that change things?

Do you have a backup image of the drive ?

How old is it (i.e. is the backup image relevant
or irrelevant at this point) ? A really old backup
isn't much good if you're about to lose a lot of
data files.

In a previous thread, you're missing a SYSTEM registry file.

In this thread, you're missing some small boot ingredient.

I'd want to boot some environment, where I could look
at the volume in question. Even booting the Win10 installer
DVD is better than nothing. In the troubleshooting section,
it has a Command Prompt button. From there, you can "dir C:"
or "dir D:" and so on.

Testdisk has a list files option, which you could test if
the volume isn't too trashed.

The Automatic Repair may have already tried to run CHKDSK.
At one time, it would spend two hours doing a bad block
scan, but doesn't seem to be doing that now. I've had
these Automatic Repairs too, but for a different
easy to fix reason. All I had to do was get into
Safe Mode (mine was a driver problem, and the BSOD error
STOP code right away gives the breadcrumb needed).

Paul