Stop code 0x0000007B: INACCESSIBLE_BOOT_DEVICE

Revert recent hardware changes

Only if Windows doesn't start (the page lists this under 'If you're unable to boot Windows'): remove any recently added hardware, especially hard disk drives or controllers, to see if the error is resolved. If the problem hardware is a hard disk drive, its firmware might be incompatible with your version of Windows; contact the manufacturer for updates. If removing another device fixes it, IRQ or I/O port conflicts might exist; reconfigure the new device according to the manufacturer's instructions.

Undo recent UEFI (BIOS) changes

Only if Windows doesn't start (the page lists this under 'If you're unable to boot Windows'): if you recently changed UEFI (BIOS) settings, such as switching the controller mode from legacy to AHCI, revert those changes.

Our advice: Back up your files first, and follow your PC maker's instructions for BIOS or firmware settings and updates. How to: Windows recovery environment

Check storage compatibility

Only if Windows doesn't start (the page lists this under 'If you're unable to boot Windows'): confirm that all hard disk drivers, hard disk controllers and other storage adapters are compatible with the installed version of Windows.

Update UEFI (BIOS) and firmware

Only if Windows doesn't start (the page lists this under 'If you're unable to boot Windows'): check for updates for the system UEFI (BIOS) and the storage controller firmware.

Our advice: Back up your files first, and follow your PC maker's instructions for BIOS or firmware settings and updates. How to: Windows recovery environment

If Windows boots: Safe Mode, then a normal restart

Safe Mode loads a core set of storage drivers. On Windows 11, open Settings > System > Recovery and select Restart now next to Advanced startup (Microsoft's 'Windows recovery environment' page); on Windows 10, the bug check page's path is Settings > Update and Security > Recovery > Advanced startup. Then choose Troubleshoot > Advanced Options > Startup Settings > Restart, and choose option 4, 5 or 6. Once Windows is loaded in Safe Mode, restart normally to see whether the storage device is recognized.

If the device is encrypted with BitLocker, you need its BitLocker recovery key to change startup settings (Microsoft's 'Windows startup settings' page).

Microsoft advises: Keep track of what you change so you can undo it, and return the PC to a normal startup when you are done. (How to perform a clean boot in Windows)

Start WinRE and open Command Prompt

Written for IT administrators.

Start the system from installation media for the installed Windows version.

On the Install Windows screen select Next > Repair your computer, then on System Recovery Options select Next > Command Prompt.

Check that the boot disk is visible

Written for IT administrators.

At the WinRE prompt run diskpart, then list disk. UEFI computers show an asterisk in the GPT column.

If the OS disk is listed, run list vol. If the OS disk isn't listed, the page says to engage the OEM or virtualization manufacturer.

Check the Boot Configuration Database

Written for IT administrators.

Run bcdedit at the WinRE prompt. Check that the {bootmgr} device and path, and the {default} device, path, osdevice and systemroot, point to the right places.

If something is wrong or missing, the page recommends backing up the BCD first with: bcdedit /export C:\temp\bcdbackup (restore with bcdedit /import C:\temp\bcdbackup; the page says this overwrites all BCD settings).

Microsoft advises: Back up the BCD store before you change it: bcdedit /export C:\temp\bcdbackup makes the backup, and bcdedit /import C:\temp\bcdbackup restores it (the import overwrites all BCD settings). (Advanced troubleshooting for Stop error 7B or Inaccessible_Boot_Device)

Fix BCD entries (only if wrong or missing)

Written for IT administrators.

Only after the BCD backup is done (the page says to run this after the backup completes), run: bcdedit /set *{identifier}* option value (example from the page: bcdedit /set {default} device partition=C:).

To completely re-create the BCD, or if you get "The boot configuration data store could not be opened. The system could not find the file specified," run: bootrec /rebuildbcd

Microsoft advises: Back up the BCD store before you change it: bcdedit /export C:\temp\bcdbackup makes the backup, and bcdedit /import C:\temp\bcdbackup restores it (the import overwrites all BCD settings). (Advanced troubleshooting for Stop error 7B or Inaccessible_Boot_Device)

If it started after a Windows Update install

Written for IT administrators.

Check installed packages with: Dism /Image:<Specify the OS drive>: /Get-packages

Run: dism /Image:C:\ /Cleanup-Image /RevertPendingActions (replace C: with the system partition).

Check whether \Windows\WinSxS\pending.xml exists on the OS drive; if it does, rename it to pending.xml.old.

The page then continues with offline registry steps (loading the COMPONENTS and SYSTEM hives in Registry Editor to remove pending entries); they are not repeated here - follow the page for them.

Microsoft advises: Back up your important files before you start. If BitLocker is on, you'll need your BitLocker recovery key for most recovery options in Windows RE. (Recovery options in Windows)

Microsoft advises: Only try this if you're comfortable working in the command line, and back up your personal files first. (Troubleshoot problems updating Windows)

Last resort: clean install from installation media

A clean install erases all files, apps and settings on the drive where Windows is installed (Microsoft's 'Recovery options in Windows' page). Try it only if Windows still doesn't start and none of the steps above helped.

The bug check page lists it last under 'If you're unable to boot Windows': on another computer, use the Media Creation Tool to create a bootable USB drive or DVD, and use it to perform a clean install. You might need to change the boot order in the UEFI (BIOS) menu to boot from USB or DVD; the boot menu key depends on the PC maker (commonly F12, ESC, F9, F10 or F8).

Microsoft advises: A reset or reinstall can remove your apps, settings and personal files, and a clean install removes everything on the drive. Back up your important files first, and if BitLocker is on, have your BitLocker recovery key ready. (Recovery options in Windows)