On starting up this morning I get a prompt that
the C: drive needs repairing, & that I should
restart.

I did, and the computer did the chkdsk & repair
routine.

It then restarted and the system stopped at auto
repair and then went to the blue screen with the
usual options to either restart, restore etc.

I chose restart & the computer restarted as
normal. Of course I rushed to do an image backup.

The "HD Tune" found nothing wrong.

What's going on?

Among others, this figures prominently in Event
Viewer.....
https://postimg.cc/F1Shsg0n