The unmountal boot volume can be fixed by replacing hardware but this also replaces the software and the software may be the problem.
The UNMOUNTABLE_BOOT_VOLUME bug check has a value of 0x000000ED.
This indicates that the I/O subsystem attempted to mount the boot volume and it failed.
If you want to troubleshoot the software that can be done.
(drive file system, boot files, operating system, etc.)
Find a flash drive that you can format ( > or = 8 GB)
Create a bootable windows 10 iso:
Download Windows 10
If you prefer the drive replacement that will be faster.
If you prefer to troubleshoot indicate when you have the iso ready and steps can be posted into the thread.
For the steps please use a camera or smart phone camera to take pictures and post images of the commands and results into the thread.
These steps are similar.:
How to Fix an Unmountable Boot Volume in Windows 10
The steps that can be provided will be more detailed.
If attempts to boot to the Windows 10 iso fail you can also try Kyhi boot rescue.
Windows 10 Recovery Tools - Bootable Rescue Disk - Windows 10 Forums
If Kyhi boot rescue works then you can test the drive using
HD Tune (Health or SMART, Benchmark, and Full error scan) > post images of the result into the thread
https://www.hdtune.com/
Crystal Disk
CrystalDiskInfo Crystal Dew World
Macrorit:
Check Hard Disk for Bad Sectors | Scan Disk on Windows
etc.
Followed by chkdsk /r