Fixes / Windows · Checked September 30, 2026

Windows INACCESSIBLE_BOOT_DEVICE: what it means and how to fix it

Short answer

INACCESSIBLE_BOOT_DEVICE (stop code 0x7B) means Windows lost access to the drive it boots from partway through startup. It usually follows a BIOS/UEFI storage setting change, a Windows update, or new hardware. The fix that works most often: open the BIOS/UEFI and set the storage controller mode back to what it was when Windows was installed (usually AHCI, sometimes RAID/Intel RST). Then restart.

What this message means

Windows starts loading, then needs a storage driver to read the disk it was installed on. If that driver can't start, can't see the disk, or can't recognise the file system on it, Windows stops with bug check 0x0000007B, INACCESSIBLE_BOOT_DEVICE. Because the crash happens before Windows finishes loading, you usually can't get to the desktop. The PC often restarts into a loop or ends up on the Automatic Repair screen. Your files are normally still on the drive. The problem is almost always a setting, a driver, a half-installed update or damaged boot files. A failing disk is less common but possible.

Common causes

Cause	How to tell
The storage controller mode in BIOS/UEFI was changed (AHCI, RAID, Intel RST/VMD, IDE)	The error began after a BIOS update, a CMOS reset, a dead motherboard battery, or you changing BIOS settings. In the BIOS, the SATA or storage mode is not the one Windows was installed with.
A Windows update failed to install and left changes pending	The blue screen showed up on the first restart after an update. You may have seen "Working on updates" or "Undoing changes" just before it.
The boot drive was moved, cloned or given a different controller	You recently cloned an HDD to an SSD, swapped the motherboard, moved the drive to another PC, or added an NVMe drive or adapter card.
Damaged boot files (BCD) or a corrupted file system	It followed a power cut, a forced shutdown, or partition resizing with a disk tool. Startup Repair reports that it couldn't repair your PC.
Third-party storage filter drivers, such as encryption, backup, antivirus or RAID software	The crash started after you installed or removed software that works at disk level (disk encryption, imaging and backup tools, some antivirus products, vendor RAID utilities).
A failing drive, loose cable or faulty controller	The drive is missing or keeps disappearing in the BIOS boot list. In WinRE Command Prompt, diskpart's list disk doesn't show it. You may hear clicking, or chkdsk finds bad sectors.

How to fix it

1. Undo recent hardware and BIOS changes

Shut down and unplug USB drives, docks, card readers and any disk or adapter card you added recently. Then try to boot.
If the error continues, restart and open BIOS/UEFI setup. The key is usually F2, Del or Esc, and F10 or F1 on some brands.
Find the storage setting, usually named SATA Mode, SATA Operation or Storage Configuration. On Intel laptops it may be called VMD Controller or Intel RST.
Set it back to what Windows was installed with. If you don't know, try AHCI first. If AHCI still gives 0x7B, try RAID/Intel RST (or turn VMD back on).
Check that the Windows drive is first in the boot order. Save with F10 and restart.
If you updated the BIOS recently, check whether the update reset the storage mode, and look for a newer BIOS or SSD firmware from the manufacturer.

2. Open Windows Recovery and run Startup Repair

Windows 10 and Windows 11

Turn the PC on. When the Windows logo appears, hold the power button until it switches off. Do this twice. On the third start, Windows should show the Automatic Repair screen.
Select Advanced options > Troubleshoot > Advanced options > Startup Repair.
If Automatic Repair never appears, create a Windows installation USB on another PC with Microsoft's Media Creation Tool. Boot from it, select Next > Repair your computer.
Let Startup Repair finish and restart. If it says it couldn't repair your PC, continue with the next fix.

3. Remove the update that caused it, or use System Restore

Windows 10 and Windows 11, from the Windows Recovery Environment

In Windows Recovery, go to Troubleshoot > Advanced options > Uninstall Updates.
Choose Uninstall latest quality update first. If that doesn't help, try Uninstall latest feature update.
If you still get the error, go to Troubleshoot > Advanced options > System Restore and pick a restore point from before the problem started.
If Windows asks for a BitLocker recovery key, get it from aka.ms/myrecoverykey on another device, signed in with the same Microsoft account.

4. Revert pending update actions from Command Prompt

For when Uninstall Updates fails or isn't offered

In Windows Recovery, open Troubleshoot > Advanced options > Command Prompt.
Find your Windows drive letter, which is often D: here and not C:. Type diskpart, then list vol, find the large NTFS volume, then type exit.
Run: dism /Image:D:\ /Cleanup-Image /RevertPendingActions (replace D: with your Windows drive).
Check D:\Windows\WinSxS for a pending.xml file. If one is there, rename it: ren D:\Windows\WinSxS\pending.xml pending.xml.old
Close Command Prompt and select Continue to start Windows.

5. Check the disk and rebuild the boot files

Windows Recovery Command Prompt. If BitLocker is on, unlock first with: manage-bde -unlock D: -RecoveryPassword <your 48-digit key>

Type diskpart, then list disk. If your Windows disk isn't listed, the problem is hardware (drive, cable or controller mode), so go back to Fix 1 or check the drive.
Type exit, then run chkdsk D: /f /r to repair file system errors. It can take an hour or more on large drives.
Run sfc /scannow /offbootdir=D:\ /offwindir=D:\Windows to repair system files.
On UEFI PCs, rebuild the boot files with bcdboot D:\Windows /f ALL. If that fails, assign the EFI (FAT32) partition a letter and use bcdboot D:\Windows /s S: /f ALL.
On older BIOS/MBR PCs, run bootrec /fixmbr, bootrec /fixboot and bootrec /rebuildbcd. If bootrec /fixboot says "Access is denied", use the bcdboot command from the previous step instead.
Restart and test.

6. Reset or reinstall Windows

Copy your files off first if you can. Boot a Windows installation USB, open Command Prompt from Repair your computer, and copy with robocopy or xcopy to an external drive. Or connect the drive to another PC.
In Windows Recovery, select Troubleshoot > Reset this PC > Keep my files.
If the reset fails, boot from the installation USB and do a clean install. On newer Intel laptops that don't list the drive during setup, load the Intel RST/VMD driver from the PC maker's support site.
If a clean install still hits 0x7B or can't see the disk, the drive or controller is likely faulty. Run the maker's hardware diagnostics.

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Still not fixed?

If none of these work, check whether the drive still appears in the BIOS/UEFI and in diskpart's list disk. If it doesn't, or it disappears now and then, suspect the SSD/HDD, its cable, or the M.2 slot, and run the PC maker's built-in diagnostics (for example Dell F12 > Diagnostics, HP F2, Lenovo Diagnostics). For a work computer, contact your IT department before changing BIOS settings, because BitLocker and managed RAID setups can lock you out. Otherwise, contact the PC or drive manufacturer's support with the exact stop code and what changed just before it started.

Questions people ask

Will I lose my files because of INACCESSIBLE_BOOT_DEVICE?

Usually not. The error means Windows can't reach the drive during startup, not that the data is gone. Try the non-destructive fixes first (BIOS mode, Startup Repair, uninstalling updates), and copy your files off before any reset or reinstall.

Should the SATA mode be AHCI or RAID?

It should be whatever Windows was installed with. Most desktops use AHCI, but many newer Intel laptops ship with RAID/Intel RST or VMD turned on. Switching away from the original mode without preparing Windows is one of the most common triggers for this error.

Why did INACCESSIBLE_BOOT_DEVICE appear after a Windows update?

A storage-related update or driver may have been left half-installed, so the boot driver doesn't load. Use Troubleshoot > Advanced options > Uninstall Updates in Windows Recovery. If that isn't enough, use DISM's /RevertPendingActions from Command Prompt.

Does INACCESSIBLE_BOOT_DEVICE mean my SSD is dead?

Not necessarily. Settings, updates and drivers cause it far more often. If the drive is missing from the BIOS and from diskpart's list disk, or chkdsk reports bad sectors, a failing drive becomes the likely cause.

Why do I get this error after cloning to a new SSD?

The clone may be connected through a different controller (for example SATA to NVMe, or AHCI to RAID), or its boot partition may not have copied correctly. Match the BIOS storage mode, make the new drive first in the boot order, and rebuild the boot files with bcdboot if needed.

Sources

Related errors