Inaccessible boot device after latest insider update this morning (build 21364)

Hi i just installed that particular driver update that you mention, and it caused my pc to bsod on boot with the "boot drive inaccessible" code.

I've regained access through some recovery mode and bios tinkering. But i would very much like to be able to remove it, which seems impossible.

I had to disable rezisable bar in the bios in order to retain csm mode.

It seemed to work. But definately a wonky workaround

Same for me. I had just changed my thermal paste on my cpu, so when this update came, at first I thought I did something wrong with my hardware, because my bios was also reset and could not boot anymore. This is unacceptable from Microsoft. We are power users, but imagine the mess for the normal persons it is when they see this issue and don't know what to do. I only hope this has not damaged my hardware in any way.

Nothing works in the recovery mode as it cannot back out the update, cannot repair. 

One of the update is kb5003399 and I forgot the other one, will have to boot back to the command prompt.

In the command prompt, I can tell it's not showing my 1TB drive, it's in x:/ with very little space.

Also, wusa.exe doesn't exist in that command prompt. 

Can anyone help to get my system booting again?

MB: GIGABYTE X570 AORUS ELITE WIFI AM4 AMD X570

CPU: AMD RYZEN 5 3600 6-Core 3.6 GHz

GPU: Nvidia 1070<feff><feff>

Memory: 64 GB (4 x 16 GB Crucial Ballistix 32GB Kit (2 x 16GB) DDR4-3600 )

Drive: Samsung 1TB 970 EVO NVMe M.2 Internal SSD

I had the same problem. The update also made my settings in the bios default to factory settings.   Just by luck I did a 'clonezilla' back up of the entire drive a few days ago. My solution was to reboot with the 'clonezilla' usb drive in and then press 'f12' and choose it. I then restored the entire windows drive successfully. I wish I could help you more. I seem to recall a setting in windows that allows you to go back before an update but you would need to be in windows to do it, assuming that would work.

+1 - I was in the middle of reinstalling windows and was extremely confused why I had inaccessible boot device only after windows update did its thing on the fresh install.  3 Fresh installs later and finally found this thread to isolate it.

Aorus Master x570 w/5900x

Gigabyte X570 master, I experience same problem with inaccessible-boot-device after installing the driver

BIOS in SATA Configuration

Sata mode from to RAID

and

NVMe RAID Mode to Enable

Windows boot properly and re-detect all my drive under RAID-Controller, I decided to keep new drivers