My computer was running Windows 10. Here are my specs:
2 x 16GB G.SKILL Ripjaws V Series 288-Pin DDR4 SDRAM DDR4 2400
1 x WD Blue 3D NAND 1TB Internal SSD
1 x EVGA GeForce GTX 1080 FTW GAMING ACX 3.0, 08G-P4-6286-KR, 8GB GDDR5X
1 x Intel Core i7-7700K Kaby Lake Quad-Core 4.2 GHz
1 x ASRock Z270 Extreme 4 LGA 1151 Intel Z270 HDMI SATA 6Gb/s USB 3.1 ATX Motherboards - Intel
1 x PC Power and Cooling Silencer Mk II 750W High Performance 80PLUS Silver SLI CrossFire Intel Haswell Ready Power Supply
I was using the PC to listen to Spotify when it froze. I did a hard restart and I got the message 'Stop code: UNMOUNTABLE BOOT VOLUME'
Looking up this issue, it seems that some file got corrupted and the solution is to reinstall Windows. I still have my original instalation disc. When I put it in my Apple Superdrive and plug it in, it returns 'Reboot and Select a proper Boot device or Insert Boot Media in selected Boot device and press a key'. I then create a bootable drive to try that way using the image found 
Link Removed. I first try with Boot Camp Assist but I get the same issue. I then use this series of commands in the terminal in order to create another boot drive after formatting the drive as FAT through Disk Utility. 
	
	
	
		Bash:
	
	
		diskutil list
diskutil unmountDisk /dev/disk2
sudo dd if=/Users/Eddie/Downloads/Win10_1809Oct_v2_English_x64.iso of=/dev/disk2 bs=1m
diskutil eject /dev/disk2
	 
 
This is the lines used with all returned text.
	
	
	
		Bash:
	
	
		(base) Eddies-MacBook-Pro:~ Eddie$ diskutil list
/dev/disk0 (internal, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *500.3 GB   disk0
   1:                        EFI EFI                     209.7 MB   disk0s1
   2:                 Apple_APFS Container disk1         500.1 GB   disk0s2
/dev/disk1 (synthesized):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      APFS Container Scheme -                      +500.1 GB   disk1
                                 Physical Store disk0s2
   1:                APFS Volume Macintosh HD            431.2 GB   disk1s1
   2:                APFS Volume Preboot                 46.7 MB    disk1s2
   3:                APFS Volume Recovery                510.4 MB   disk1s3
   4:                APFS Volume VM                      1.1 GB     disk1s4
/dev/disk2 (external, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:     FDisk_partition_scheme                        *15.5 GB    disk2
   1:                 DOS_FAT_32 WININSTALL              15.5 GB    disk2s1
/dev/disk4 (disk image):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:                            CCCOMA_X64FRE_EN-US... +5.4 GB     disk4
/dev/disk5 (disk image):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:                            Boot Camp              +2.8 GB     disk5
(base) Eddies-MacBook-Pro:~ Eddie$ diskutil unmountDisk /dev/disk2
Unmount of all volumes on disk2 was successful
(base) Eddies-MacBook-Pro:~ Eddie$ sudo dd if=/Users/Eddie/Downloads/Win10_1809Oct_v2_English_x64.iso of=/dev/disk2 bs=1m
Password:
5138+1 records in
5138+1 records out
5388175360 bytes transferred in 3100.214460 secs (1738001 bytes/sec)
(base) Eddies-MacBook-Pro:~ Eddie$ diskutil eject /dev/disk2 
Disk /dev/disk2 ejected
	 
 
Each time I've done a manual select of whatever boot media I want to try. I'm not sure what else could be wrong here. My BIOS always sees the boot devices correctly but every time I try to use it, I get the same error message. Is there a better way to make boot media? Any ideas as to what could be wrong?