My model is Helios G3-571. Purchased over 2 years ago so out of warranty.
This happened immediately after reboot during a Windows 10 update.
I am getting this error when I try to boot from the SSD:

In the BIOS the primary SSD is still recognized.
I tried booting from a Windows 10 flash drive and running bootrec commands, e.g.
"Bootrec /fixmbr". This results in nothing other than saying the command cannot be completed due to an "I/O Error".
The "Repair" option in Windows install said it could not repair.
So then I tried to just reinstall Windows on the primary SSD.
The Windows installer shows the O/S partition as all free space, so I tried installing on that, and ended up with this result:
I decided maybe I need to first delete the partitions and repartition so I started with the "System" one and got this:

Bios (version 1.13) information tab:
Any suggestions appreciated.