Please boot from the USB setup disk and access Windows RE.
In Windows RE, click Troubleshoot, Advanced Options, Command Prompt.
In the WinRE Command Prompt, type the following commands:
mountvol y: /s
diskpart
select disk 0
list part
select part 2
assign letter=Y
list vol
exit
Take photos of the output screen using your phone and share the images here. Don't quit WinRE yet. A few more commands need to be run.