How to fix the INACCESSIBLE_BOOT_DEVICE (0x0000007B) blue screen
This stop code means Windows lost contact with the drive it boots from during startup. A changed storage controller mode, a missing driver, a damaged BCD or a recent update is usually behind it. Jump to your situation below or work through the methods in order.
By Neeraj Singh ~14 min Updated Jun 2026 86% found this helpful
Error message
INACCESSIBLE_BOOT_DEVICE. Stop code 0x0000007B. Windows lost access to the system partition during startup.
Summary
INACCESSIBLE_BOOT_DEVICE (stop code 0x0000007B) means Windows could not reach the drive it boots from early in startup. The classic causes are a changed SATA or NVMe controller mode in the BIOS (switching between AHCI, RAID and IDE so Windows no longer has the right driver), a missing or broken storage driver, a damaged boot configuration (BCD), or a recent Windows update that broke the boot path. Because Windows will not start, the fix is done from the Recovery environment or boot media: set the storage controller mode back to what Windows expects, rebuild the BCD with bootrec, and uninstall the most recent update if the crash began right after one. Checking the drive connection and SMART health rules out a failing disk.
What this error means
Very early in startup Windows must load the driver for the controller its boot drive is attached to. If that controller's mode has changed, or the matching driver is missing, Windows reaches for the drive and finds nothing it can talk to, so it stops with 0x0000007B before the desktop ever appears.
That is why a BIOS change is the classic trigger: switching the SATA mode from AHCI to RAID, or a BIOS reset reverting it, leaves Windows without the right driver. A damaged BCD or a bad update breaks the same boot path. Restoring the mode and repairing the boot files brings it back.
Common causes
The SATA or NVMe controller mode was changed (AHCI, RAID, IDE).
A BIOS update or reset reverted the storage mode.
A missing or broken storage controller driver.
A damaged boot configuration database (BCD).
A recent Windows update broke the boot path.
A loose cable or failing boot drive.
Disk corruption on the system partition.
Expert insight
“0x0000007B is Windows waking up and not finding the disk it lives on. The first thing I check is the BIOS storage mode, because flipping SATA between AHCI and RAID, or a BIOS reset doing it for you, is the classic cause, Windows simply does not have the driver for the new mode. Set it back to what it was and it usually boots. If not, I rebuild the BCD from recovery and, if this started right after a Windows update, uninstall that update from the recovery menu.”
1Reseat the drive's power and data cables, or reseat an M.2 drive.
2Check the drive's SMART health from recovery or another PC.
3A loose or failing drive causes this stop code.
Method 6
Try Safe Mode
1In the Recovery environment, choose Startup Settings and boot Safe Mode.
2If Safe Mode works, a driver or service loaded normally is the problem.
3Update the storage driver from there.
INACCESSIBLE_BOOT_DEVICE is a boot-path problem, so the first check is the BIOS storage mode: set SATA back to AHCI (or RAID if that is your setup), since a change or BIOS reset is the classic cause. If that does not boot, rebuild the BCD from recovery and uninstall a recent update if the crash started after one. Treat a failing drive as the last suspect.
Frequently asked questions
What does INACCESSIBLE_BOOT_DEVICE mean?
Stop code 0x0000007B means Windows lost access to its boot drive during startup, usually from a changed storage controller mode, a missing driver, a damaged BCD, or a recent update.
How do I fix the SATA mode?
Enter the BIOS, find the SATA or storage mode, and set it back to what Windows was installed with, usually AHCI. A recent change or a BIOS reset reverting it is the classic cause.
How do I rebuild the BCD?
Boot from recovery media, open Command Prompt, and run bootrec /scanos, bootrec /rebuildbcd, bootrec /fixmbr and bootrec /fixboot to repair the boot configuration.
It started after a Windows update
In the Recovery environment choose Troubleshoot, Advanced options, Uninstall Updates, and remove the latest update. A bad update can break the boot path and cause this stop code.
Could my drive be failing?
Possibly. Reseat the drive's cables or M.2 connection and check its SMART health. A loose or failing boot drive can trigger 0x0000007B, though a controller-mode change is more common.
How do I get into recovery if Windows won't boot?
Let the PC fail to start twice and it enters the Recovery environment automatically, or boot from Windows installation media and choose Repair your computer.
Still not working?
If the controller mode, BCD and updates are all correct and it still will not boot, the storage driver in the installed Windows may be missing for your hardware. From recovery you can inject the correct storage driver, or as a last resort perform an in-place repair install from same-build media. You can also submit your error to us for a tailored fix.
