Windows · Windows Server  ·  critical  ·  Core Windows faults

STOP 0x0000007B — INACCESSIBLE_BOOT_DEVICE

Windows reaches the point in boot where it must read the system volume and cannot, so it stops before anything is loaded from disk.

What you see

The machine posts, shows the Windows logo or the manufacturer splash, then bugchecks with 0x7B. It happens on every boot, including Safe Mode, and Last Known Good does not help.

What is actually wrong

The boot-critical storage driver is not loaded. Almost always one of three things: the SATA/NVMe controller mode changed in firmware, the driver's Start value was set to something other than 0 by an update or an image, or a virtual machine was moved to a host that presents a different controller.

Codes and articles

0x0000007B0x7BINACCESSIBLE_BOOT_DEVICEKB2673509

Fixes (2)

Put the storage controller back to the mode Windows was installed under
Firmware / BIOS setup5 minuteslow riskreversible

The controller mode was changed, a firmware update reset it to defaults, or the CMOS battery died.

  1. Power off, then enter firmware setup — usually Del, F2 or F10 during POST.

  2. Find the SATA / storage configuration page. Note what it is set to now.

    If this fix is wrong you want to be able to put it back exactly as it was.

  3. Switch the mode: if it is on RAID or Intel RST, set AHCI. If it is on AHCI and the machine was built with RST, set RAID.

    Windows only loads the one storage driver it was told to expect at install time. Changing the controller mode changes which driver is needed, and the other one is not started.

  4. Save and exit. Let it boot.

Confirm it workedWindows reaches the sign-in screen. If it does, the mode was the problem and nothing further is needed.
If you need to undo itSet the mode back to what you noted in step 2 and use the driver fix below instead.
Re-enable the boot storage driver offline from WinRE
Windows Recovery Environment (command prompt)10–15 minutesmedium riskreversible

Firmware is correct, or you need Windows to load a driver it currently has disabled. This edits the offline registry, so read the rollback note first.

  1. Boot from Windows installation media (or hold Shift while clicking Restart) and go to Repair your computer → Troubleshoot → Command Prompt.

  2. Identify the drive letter the Windows installation has inside WinRE. It is very often D:, not C:.

    Command Prompt
    diskpartlist volumeexit

    WinRE assigns its own letters. Editing the wrong hive silently does nothing.

  3. Load the offline SYSTEM hive under a temporary key.

    Command Prompt
    reg load HKLM\OFF D:\Windows\System32\config\SYSTEM

  4. Set the boot-start drivers to load. Run all of these — the ones that do not apply simply have no effect.

    Command Prompt
    reg add "HKLM\OFF\ControlSet001\Services\storahci" /v Start /t REG_DWORD /d 0 /freg add "HKLM\OFF\ControlSet001\Services\stornvme" /v Start /t REG_DWORD /d 0 /freg add "HKLM\OFF\ControlSet001\Services\iaStorV" /v Start /t REG_DWORD /d 0 /freg add "HKLM\OFF\ControlSet001\Services\msahci" /v Start /t REG_DWORD /d 0 /freg add "HKLM\OFF\ControlSet001\Services\pciide" /v Start /t REG_DWORD /d 0 /f

    Start=0 means boot-start: the driver is loaded by the boot loader before the disk is needed. Anything else is too late to read the system volume.

  5. If list volume showed more than one control set, repeat step 4 against ControlSet002.

    Command Prompt
    reg query HKLM\OFF /f ControlSet00* /k

  6. Unload the hive cleanly. Do not skip this — an unloaded hive can be left locked.

    Command Prompt
    reg unload HKLM\OFF

  7. Exit and restart.

Confirm it workedWindows boots. Once in, confirm the controller driver is running.
PowerShell
Get-Service storahci, stornvme | Format-Table -AutoSize
If you need to undo itBoot WinRE again, load the hive as in step 3 and set the Start value back to 3 (manual) for whichever service you changed. If the machine will not boot at all afterwards, restore the SYSTEM hive from C:\Windows\System32\config\RegBack if your build still populates it.

Reference

Bug Check 0x7B — Microsoft Learn ↗

Related faults

STOP 0x00000133 — DPC_WATCHDOG_VIOLATIONWindows0xC000021A — STATUS_SYSTEM_PROCESS_TERMINATEDWindowsSTOP 0x0000009F — DRIVER_POWER_STATE_FAILUREWindowsSTOP 0x00000139 — KERNEL_SECURITY_CHECK_FAILUREWindowsSTOP 0x0000001E — KMODE_EXCEPTION_NOT_HANDLEDWindowsSTOP 0x00000050 — PAGE_FAULT_IN_NONPAGED_AREAWindows

Where this stops. This write-up was written and checked by hand. It says what each step changes, how to confirm it worked and how to reverse it, and anything destructive is flagged before you reach it. If it does not match what your machine is doing, search the Support Centre for the exact code or message — and when something needs a person, get in touch.