Win 10 crashed and stopped booting from Dual boot.

Launch the Command Prompt. Press 'Enter' after every command & Share the Snapshot of the results.

Diskpart

List disk

Select disk 0

Replace 0 with Windows 10 Disk no.

List Partition

1.Take Care! : You are supposed to delete Reserved & System partitions one by one.

Diskpart

List Disk

Select Disk 1

List Partition

Select Partition 1

Delete Partition

Exit

Diskpart

List disk

select disk 1

List Partition

Select Partition 1

( 1 Refers to System Partition )

Delete Partition

Exit.

2. Creating EFI Partition with Command Prompt.

Disk Part

List Disk

Select Disk 1

Create Part EFI

format fs=fat32 quick

Exit.

3. Shut Down & Detach the Windows 7 Disk. Boot into the Recovery Media & Try Macrium Reflect > Fix Boot Errors.

When completed. Shut Down. Take Out the Pen drive & Try to boot into Windows 10.

Let me know.

UPDATE : By System Partition, I am referring to EFI partition which is showing as System partition in Diskpart.

ShaneSaunders said:

I have a couple questions before I do all that...
Are you sure I have to delete both of the first two partitions? One is Reserved and the other is for the EFI. What would happen if I delete the Reserved partition?
Also, can you look through your checklist again? I haven't created an EFI with command prompt in this way. I just don't want to accidentally format the main partition with all my data.
Also, I am wondering if the issue is something else, as I got the 0xc000021a when I booted from both the Windows 7 Boot Menu booting from that disk, and from the Windows 10 Boot when I booted from that disk

I appreciate your concerns & feedback and ask you to follow my senior. He is better equipped to steer you through the way.

@NavyLCDR : Sir, we need & request your help & guidance in the matter!

Thanks. ...

1.

NavyLCDR said:

Post #17 indicates that the installation of Windows 10 is corrupt and it needs to be reinstalled.

Thanks Sir.

2. @ShaneSaunders : You will be wanting to copy your personal interest files such as Documents, Music, Downloads, items on Desktop, etc. from the Windows 10 disk. You can easily proceed Windows 10 partition drive letter ( H: ) > Users > User Name > Desktop, Downloads, Music, etc. folders. There will be as many users as you made + 2. For eg. a person who made / used only one admin account will see 3 users : Default, Created One & Public. I will advise you to don't mess with system files there, you will be able to make out your personal interest files instantly by just having a look at them. I will advise you to do that from the Recovery media itself & don't endanger your windows 7 or other OS installations.

3. You expressed the wish to make System Images. To be very clear, System Images actually copy the occupied space of the System Crucial Partitions & compress them to make the image file smaller & size efficient. They do differential, Incremental etc. other things for the consecutive system Images!
If there are so many personal interest files on C: partition as you are having, the size of System Image(s) will be so big that it will not be practical & realistic to make System Images regularly. I make a separate data partition for my personal files & the size of occupied space in my C: partition does never go beyond 50 GB!
For the same reason people change the Default Folder Location to a separate data partition. To avoid any problems, I will like to change the location only for Documents, Videos, Music, Downloads, etc. very personal data folders though I have never done that. I copy & place the files manually to a separate data partition.

Thanks. ...

EDITED : TO MAKE THE THINGS CORRECT!

ShaneSaunders said:

Before I do the whole reinstall thing. Would either of the next two options work?
Using : DISM /Online /Cleanup-Image /RestoreHealth /Source:F:\Sources\install.wim
or using the Reset This PC option from the Windows 10 troubleshoot option from the Blue Screen repair menu?
Could the DISM option allow me to retain my apps?

Hi,

To be honest : I still feel we can try a few things but running very short of time. Sometimes I come to the PC when it is already 12 o' clock night at your side. You will have to be very very patient. Is it possible ? If yes, then let's proceed one by one!

1. Copy your personal interest files to another disk as I have pointed out in my last post. It will safe guard your data. Besides, It will drastically shorten the length & ease up the troubleshooting process.

2. Try to Boot Into Safe Mode ( Option 1 should work for you )
There are 3 options for Safe Mode. First try to boot into 'Safe Mode'. On success, try 'Safe Mode with Networking' & 'Safe Mode with Command Prompt'.

3. When in 'Safe Mode with Command Prompt' try to run the Dism Command

Dism /Online /Cleanup-Image /ScanHealth

. If it reports any corruptions, Then only one should look for RestoreHealth, etc. commands.

4. If we are able to Boot Into Safe Mode, I will put a query to our BSOD experts to know whether we can follow the BSOD - Posting Instructions from 'Safe Mode With Command Prompt'.

Let me know.

Thanks. ...

ADDED : As for Windows 10's 'Reset' & 'Refresh' options, they will not keep your Apps, Drivers & Settings. For more info see the Options table There! : As to what 'Reset' & 'Refresh' options can keep! The tutorials for them : Reset & Refresh .