[SOLVED] Motherboard no longer detects Windows SSD as a bootable drive after LinuxUSB/firmware update.

Cyber_Akuma

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Oct 5, 2002
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CPU: i7-10700K
Motherboard: Z490 Aorus Pro AX
RAM: 2x32GB DDR4 3600 G.Skill

I was setting up a new system. First thing I did was install Windows on a temporary SSD to test different drivers, run stress testing, and just check out various other things without having to worry about trashing a more permanent install.

Afterwards I physically disconnected said SSD and plugged in a USB drive that I installed (not just as a live-usb) Linux on to further test some things. During this time there was a firmware update for my motherboard that updated my CPU microcode and added resizable BAR so I installed it. It reset my BIOS settings but I re-set them to what I am pretty sure was the original settings.

After I was done with Linux I plugged the SSD back in to check some further stuff out and Windows would not boot. And by "not boot" I don't mean it gives an error or something, I mean the motherboard just kicks me into the bios and doesn't even see a bootable drive at all. It does see the SSD itself, and I can see that all it's files are still on it, but it does not even list it among bootable devices or try booting it.

So I setup said USB drive as a Windows installer so I can run startup recovery. It would fail. I tried to manually do it through the command prompt, but I would get a "Access Denied" error for /fixboot. When I tried "rebuildbcd" it finds the Windows installation, but then errors out with "The requested system device could not be found". After this, I was having trouble getting the USB drive to even boot, it giving me a boot error in /efi.

I tried adjusting the UEFI/Legacy and Secure Boot settings of my motherboard, and noticed that my motherboard was setting two ways to boot said USB drive, and was apparently trying to boot it in BIOS mode where it was failing. I manually made it boot in UEFI mode and this not only seemed to make it boot properly, but nowe repair install appeared to actually be working.

After a while at the "attempting repairs" screen however it boots and...... now the USB drive won't boot in EITHER Legacy or UEFI mode, each throwing a different boot error.

Nothing made it boot again, pulling my hair out wondering if my board for some reason was so messed up that I can't even boot an OS installer anymore, I tried re-creating the USB drive and.... it works completely properly again.

Apparently for some reason instead of fixing my install on the SSD (which "Scanos" and "rebuildbcd" DOES see on the SSD itself) it somehow tried to repair the USB drive itself and wound up completely screwing it up as a result?

I am confused just what to do now if this is the case and the repair tools are for some reason seeing the install on the SSD but ignoring that and trying to repair the USB drive instead.

One of the many articles I Googled mentioned manually giving your EFI partition a letter, then formatting it and basically re-creating it's boot information (it makes specific mention that this partition needs to be FAT32).... but none of them really specify WHICH partition would be the right one. I only see three partitions on my SSD, one of them is nearly the size of the entire drive and clearly the main install, another is 500MB, and the other 50MB.... but both are NTFS and neither has any sort of "BOOT" or "EFI" label.
 
Solution
Because I still need to test some things on said temp install and I don't want to have to completely set it up from scratch again, also it would be useful to know what's wrong when I need to migrate an existing install to this system later in case I run into a similar problem.
https://docs.microsoft.com/en-us/wi...re/desktop/bcd-system-store-settings-for-uefi

Since auto repair got confused you will have to manually figure out the identifier of the ssd and add it to the bcdstore/ boot menu.
Why are you trying to fix something that was a temporary install only anyway?!
Boot from the usb and do a normal clean install.
Before that go into bios and do a reset to defaults because that's something that bios updates often recommend to make the new settings "stick" .
 

Cyber_Akuma

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Why are you trying to fix something that was a temporary install only anyway?!

Because I still need to test some things on said temp install and I don't want to have to completely set it up from scratch again, also it would be useful to know what's wrong when I need to migrate an existing install to this system later in case I run into a similar problem.

Before that go into bios and do a reset to defaults because that's something that bios updates often recommend to make the new settings "stick" .

The update already did that, but I still also chose to reset to the defaults as well.
 
Because I still need to test some things on said temp install and I don't want to have to completely set it up from scratch again, also it would be useful to know what's wrong when I need to migrate an existing install to this system later in case I run into a similar problem.
https://docs.microsoft.com/en-us/wi...re/desktop/bcd-system-store-settings-for-uefi

Since auto repair got confused you will have to manually figure out the identifier of the ssd and add it to the bcdstore/ boot menu.
 
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