Windows 10 (1803) won't boot - bootrec errors

Question

I have an MSI x99 motherboard with a Samsung M.2 1TB stick with Windows 10 installed on it. After I installed an updated nvidia driver chrome looked strange so I rebooted and got an inaccessible boot device error. I've researched online for ways to fix it but so far nothing has worked. In general, what I've seen online is booting off the Windows 10 installation media and using diskpart and bootrec in the command prompt. There are a couple variations of the commands out there. Most involve assigning a drive letter to a particular volume then running bootrec on it. I'm getting access denied from bootrec /fixboot and the request system device cannot be found with bootrec /rebuildbcd.

Here's an example - https://answers.microsoft.com/en-us/windows/forum/windows_10-update/windows-10-bootrec-fixboot-access-is-denied/747c4180-7ff3-4bc2-b6cc-81e572d546df

diskpart
sel disk 0
list vol
sel vol 4
assign letter=V:
exit
V:
format V: /FS:FAT32
bcdboot C:\windows /s V: /f UEFI  

Here's what I see -

Answer 1

Looks like my issue was with Windows 10 1809. I gave up and re-installed from scratch using the latest Windows 10 from Microsoft (1809) and kept getting a boot freeze. I then tried 1803 and never got a boot freeze. I think 1809 installed in the background and when I rebooted for something else (nvidia driver update) I got hit with the issue. I found a Reddit where other people are complaining about the same thing, even people with the same motherboard -

https://www.reddit.com/r/Windows10/comments/9l10mk/unable_to_update_windows_10_to_v1809_freezing_at/

It turns out MSI has a BIOS that is supposed to address the issue with 1809 -

https://us.msi.com/Motherboard/support/X99A-XPOWER-GAMING-TITANIUM

Version: 7A21v161(Beta version)

Release Date: 2018-06-16

File Size: 6.62 MB

Description - Improve Windows10 1809 stability.