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April 3rd, 2025 15:31
boot fail stopcode inaccessible boot device xps 15 9520 after April 1 2025 firmware update
Hello,
My computer failed to boot April 2. Rebooting resulted in stop code "inaccessible boot device". I went into BIOS and the boot SSD is still recognized. Then I noticed in the system log that there was a firmware update the night prior, so it seems possible that the firmware update bricked the computer by making it impossible to boot from the primary SSD.
How do I fix this? The recovery system starts up after recognizing the boot failure but none of the options give me a chance to revert to a prior bios firmware version. I have firmware reversion options turned on in bios but since the system doesn't recognize it as a bios failure, it isn't rolling back the firmware automatically.
It seems like I should at least try a bios reversion before attempting to restore the OS through the recovery menus, since I can't tell if it's a firmware issue or an actual failed SSD. Since the SSD is recognized in bios but won't boot, I'm not confident that a recovery will help but it might actually wreck the existing windows installation and make any files unrecoverable.
Suggestions? I'm leaning towards a BIOS reversion but I don't even know how to do that. Thanks in advance!
flensr
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April 5th, 2025 21:27
Hopefully final update:
I removed the boot SSD and manually copied all user files to an archive location, then reinstalled the SSD.
I reflashed the bios back up to 1.30.0 and set bios options to default.
Restarted, still had the same problem.
Tried the following system recovery options without success:
Repair startup
Safe mode
Boot with security and driver signature checks disabled
I then tried reverting to the last system restore point created just prior to the latest windows and bios updates (still using the recovery tools) and this resulted in a bootable system. It had a number of app and driver startup failures after the first bootup but these may have been due to booting with no network available. But things like microsoft defender and mobile devices gave startup errors saying they could not run.
I'm still in the process of determining what has bee lost and investigating exactly what update caused the problem, but basically the last set of windows updates and bios update which automatically installed on 3/30/25 (restore point was created 3/27/25) and automatically rebooted on 4/1/25 is what bricked it and reverting to the 3/27/25 restore point got the system bootable again.
flensr
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April 3rd, 2025 15:35
Update - The installed bios is 1.30.0.
flensr
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April 3rd, 2025 18:23
Second update, I tried the tips from the other older thread and they didn't work. I tried:
Disabling secure boot
Disabling VT for direct I/O - required me to disable another virtualization option in bios, but also did not work.
I did not get a bitlocker key request so either bitlocker isn't installed or the boot process isn't getting far enough for it to even ask.
My next step is to regress the bios to a previous version (It has the latest 1.30.0 installed). After that I'll have to try using the dell troubleshooter tools to revert to a restore point which will hopefully undo whatever was done on April 1 when it automatically installed at least the firmware update and possibly other windows updates.
flensr
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April 3rd, 2025 18:50
Another update - regressing bios to 1.29.0 did not help. Same BSOD inaccessible boot device.
The only other thing I can try is a system restore but I'm going to hold off on that hoping someone will offer a real solution.
Chino de Oro
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April 3rd, 2025 22:53
Check BIOS settings to see the current storage controller mode and switching between RAID and AHCI from current one.
flensr
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April 3rd, 2025 23:12
@Chino de Oro It was set to RAID. I switched it to AHCI and it still won't boot.
Chino de Oro
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April 3rd, 2025 23:30
If the boot drive was originally imaged from Dell, restore the BIOS settings to default value should help if the inaccessible boot device error was caused by conflicted settings.
Start your system and keep tapping F12 at Dell logo to access one time boot menu. Select diagnostics to scan the system for any hardware issue, especially the boot drive.
If no hardware issue, you can perform a clean Windows installation with BIOS settings at default value. Your system should be up and running a couple hours from now.
flensr
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April 4th, 2025 00:54
@Chino de Oro I reset BIOS to defaults and it still won't boot. I ran the complete advanced diagnostics and there were no faults detected.
I would rather not do a clean windows installation because my wife had made a significant amount of updates to some important documents in the few days after our last system backup, and I would like to be able to recover those documents and not have to completely set up her system from scratch again.
Plus... Even if I do a clean windows install, will another update brick it again anyhow? There appears to be "nothing wrong" with the hardware, but after the automatic update and firmware update it won't boot. That seems to indicate that there is a big problem with either the windows update or the BIOS and since I regressed the bios back to 1.29.0 without that fixing the problem, there seems to be a major OS conflict in there somewhere that bricked the system.
I still haven't used the Dell utility to revert to a system restore point, but I'm wondering if I should pull the SSD out and try to manually copy off her user files before trying the restore point. My preference is to not lose a week of work and then waste another week getting the computer properly configured again after a clean install.
Chino de Oro
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April 4th, 2025 03:14
It's all up to you to choose resolution, but learning from mistake, backup was always needed. Since you are going to rebuild the system from scratch, think of the upgrade you want/need and include into the working plan. For example, replace the boot SSD with a larger capacity before Windows installation. Put the old SSD into an enclosure to become a large capacity USB drive, then accessing user folder for backup files.
When the diagnostics have passed everything, then the error you are facing was simply software related. Because of EFI boot file/partition could not be located, or the drive's drivers (RAID/AHCI) does not existed/corrupted. Unless you have advance knowledge to repair the EFI boot partition and installing proper storage driver, worry about time consuming does not help or change the fact that you still need to fix Windows for it to work proper again.