Windows BSOD Error 0x0000007B — INACCESSIBLE_BOOT_DEVICE Fix

What it means

Error 0x0000007B means Windows cannot access the drive it needs to boot from.
This is called INACCESSIBLE_BOOT_DEVICE.
Think of it like arriving home to find your front door locked and you do not have the right key — Windows can see that a boot drive should be there, but cannot open it.
Common causes include a loose drive cable, wrong BIOS storage settings, or a corrupted boot driver.

Affected Models

Windows 10
Windows 11
Windows 8.1
Windows 7
Windows Server

Common Causes

The SATA or NVMe cable connecting the boot drive is loose or faulty
The BIOS storage mode was changed from AHCI to IDE (or vice versa) without updating Windows drivers
The storage controller driver required to access the boot drive is missing or corrupted
The Master Boot Record (MBR) or boot partition is damaged
A new SSD or NVMe drive was installed and Windows does not have the correct driver for it

How to Fix It

Check physical drive connections. Open your PC case and verify the data cable from the motherboard to the boot drive is firmly seated. Unplug it and plug it back in. Also check the power cable to the drive.

A loose cable is one of the most common causes of this error — especially after moving the PC or adding new hardware.
Check BIOS storage mode settings. Restart and enter BIOS/UEFI (usually by pressing F2, F10, or Delete at startup). Find the storage controller settings and confirm the mode matches what Windows was installed with (usually AHCI for modern systems).

If you recently changed from AHCI to IDE or back, Windows may not have the driver for the new mode.
Return it to the original setting.
Run Startup Repair from the Windows Recovery Environment. Force it by turning the PC off three times during boot. Choose Troubleshoot > Advanced options > Startup Repair.

Startup Repair can restore missing boot drivers and fix the Boot Configuration Data (BCD) that tells Windows where the drive is.
Rebuild the Boot Configuration Data manually. In the recovery Command Prompt, type these commands one at a time: bootrec /fixmbr — then bootrec /fixboot — then bootrec /rebuildbcd

These commands repair the master boot record and rebuild the list of drives Windows knows how to boot from.
Repair the AHCI driver. If the BIOS mode cannot be changed, you can enable the AHCI driver in Safe Mode first. In recovery Command Prompt, type: bcdedit /set {default} safeboot minimal — restart, let Safe Mode load, then restart normally.

This forces Windows to load the AHCI driver on the next regular boot.
After a successful normal boot, remove the safeboot flag: bcdedit /deletevalue {default} safeboot

When to Call a Professional

If you have checked the cables and BIOS settings and the error persists, a technician can test the drive health and attempt a more thorough repair.
A failing drive may need to be replaced, and professional data recovery may be needed if files cannot be reached.

Frequently Asked Questions

What is AHCI mode and why does it matter?

AHCI (Advanced Host Controller Interface) is the modern way for a PC's motherboard to communicate with storage drives.
The older mode is called IDE.
Windows installs different drivers depending on which mode is active in the BIOS at the time of installation.
If you change the mode after Windows is installed, Windows may crash at boot because it loaded the wrong driver for the new mode.

Can a Windows update cause this error?

Rarely, but yes.
A Windows update that modifies storage drivers can sometimes cause this error — especially on systems with NVMe SSDs or unusual storage controller configurations.
If the error started right after a Windows update, try uninstalling the update from the recovery environment.

I just installed a new SSD. Is that why this is happening?

Possibly.
If you cloned your old drive to a new NVMe or SSD, Windows may lack the correct driver for the new storage controller.
The fix is to boot into the Windows Recovery Environment and run Startup Repair, which should detect the new drive and install the correct driver.
Alternatively, boot from a Windows installer USB and run the repair install option.