Question BSOD: "Inaccessible_Boot_Device" after updating BIOS

[Todor_1]

I've build this system back in 2019 and decided to give it an overhaul.
Started with applying all windows-10 updates and restarting - OK.

Then, I downloaded Bios F23 (current was F3 LOL) and flashed it using the app, which restarted my computer.
Now, it won't boot into windows, stating the error in the title of this post.

I assume the BIOS update reset my settings but no idea what they were before.
I did opt to save the old BIOS but with how janky the app is, not sure how reliable that process is, if it did anything at all.

I try to follow technology but with all that UEFI, AHCI, VDM, CSM, RST... - I have no idea what I am doing, honestly!
Reinstalling everything is the last thing I want to do, as I neglected saving my files (lesson: can't give those programmers who do all this BIOS/Boot stuff any trust!!!)

Hardware:
Gigabyte Z490 Aurus Pro AX
Intel i5-10600k
ADATA XPG SX8200 Pro 1 TB M.2-2280 PCIe 3.0 X4 NVME SSD (only one drive)

Tried loading "optimized defaults" and playing with settings quite a bit. I have a feeling I might have come close to exhausting all possible permutations of these settings, without any progress - although I haven't been able to find the "VDM" that lots of posts mention.

Rant: Would it have been so hard to program some fallback method or an actual diagnostics check a-la: "SSD is set to UEFI, BIOS is set to Legacy"

Please give me any ideas what to do?
So far, I am thinking I'll try to dig out that "saved old bios" but it's going to be a mess as I don't really have anywhere else to plug that SSD in so that I can reach in the file... Nor do I have a USB stick for Q-flash...

 

[Todor_1]

Update: I am not out of the woods yet but I have some more info for the thousands of people who will update their BIOS and run into this:
Apparently, I've installed Windows-10 while my BIOS had "Intel RST" enabled. This is some RAID controller which doesn't make sense if you are only running one storage device (like me) but I guess I enabled it because it sounded faster (it is not. AHCI is faster if you have only one non-optane drive).
Windows must boot with the correct RST/AHCI that it was installed with.

If you are wondering about VMD (my bios doesn't mention it) - it's that Intel RST! it IS a VMD made by intel.
I managed to boot in safe mode (again referring to my rant that it MUST be relatively straightforward for a system to diagnose or fallback automatically). I don't know if that's the best way but I managed to dig around the repair tools and find a command prompt, where I typed:
'bcdedit /enum' then check if Windows Boot Loader > identifier is {current} or {default} and form the following command accordingly:
'bcdedit /set {current} safeboot minimal'

Now in safe mode, I am able to see in device manager Storage conrollers that I have that intel RST - which means windows was installed with RST.

I don't care about fixing it for now, I just want to boot normally. So, my progress from now on will be based on playing with OTHER bios settings but keeping RST = ON.

 

[Todor_1]

Update: I ran 'sfc /scannow' which found some errors and fixed them.

The system will still boot into safe mode only and the command lines I've found do not work... But loading msconfig and looking in the Boot tab - can untick Safe Mode and it boots normally.

I think I am out of the woods

Was planning to upgrade my SSD (I have it lying around, bought 4 months ago LOL) anyway. So, I don't care too much about fixing things up. Just want to finish my work, save everything and find some time for a clean Windows-11 install.