The Problem
INACCESSIBLE_BOOT_DEVICE (stop code 0x0000007B) means Windows loaded far enough to look for its system drive and could not reach it. The drive is usually fine and your data is usually intact—what broke is the path to it: the storage driver, the boot configuration, or a firmware setting.
It typically appears after a Windows update, a BIOS or firmware change, a cloned drive, or moving a disk to different hardware.
Stuck in a repair loop rather than a clean blue screen? See fix the Automatic Repair loop. For BSOD basics: fix the Blue Screen of Death.
Before You Start
Have your BitLocker recovery key to hand—get it from account.microsoft.com/devices/recoverykey on your phone. Several of the steps below trigger a recovery prompt on an encrypted drive.
Step 1: Check the Storage Mode in Firmware
This is the fastest fix and the most common cause after any firmware change or CMOS reset.
- Restart and enter BIOS/UEFI—tap Del, F2, or F10 at power-on. See how to enter BIOS or UEFI settings.
- Find SATA Mode, SATA Operation, or Storage Configuration.
- It must match what Windows was installed with—normally AHCI. Dell laptops frequently ship as RAID On, and switching them to AHCI (or back) causes exactly this stop code.
- Save and exit.
If you do not know which mode Windows expects, try the other setting once. If that does not help, switch it back and continue below.
If you must switch modes permanently (RAID → AHCI), boot into Safe Mode first so Windows loads the generic driver, then change the firmware setting, then boot normally.
Step 2: Check the Drive Is Detected At All
While you are in firmware, confirm the SSD or hard drive appears in the boot device list. If it does not:
- Power off, unplug, and reseat the M.2 stick or the SATA data and power cables.
- Try a different SATA port or M.2 slot.
- A drive that is invisible to firmware is a hardware problem, not a Windows one.
Step 3: Open the Recovery Environment
Force-shutdown at the logo three times. On the next boot Windows opens Automatic Repair → Advanced options → Troubleshoot → Advanced options.
Step 4: Uninstall the Latest Update
The number-one fix when the blue screen started right after Patch Tuesday.
- Advanced options → Uninstall Updates.
- Choose Uninstall latest quality update.
- If that does not apply or fails, try Uninstall latest feature update.
- Restart.
Step 5: Run Startup Repair
Advanced options → Startup Repair. One attempt; if it fails twice it will not succeed on a third.
Step 6: Repair From the Command Prompt
Open Advanced options → Command Prompt. First identify the drive letter—it is often not C: in the recovery environment:
diskpart
list volume
Note the letter of the large NTFS volume, then exit. Substitute it below wherever you see C:.
chkdsk C: /f /r
sfc /scannow /offbootdir=C:\ /offwindir=C:\Windows
bootrec /rebuildbcd
If the boot configuration is beyond repair, rebuild it outright:
bcdboot C:\Windows /s C: /f UEFI
Step 7: Remove a Bad Storage Driver Offline
If a storage or RAID driver update caused this, you can remove it without booting Windows. From the recovery Command Prompt:
dism /image:C:\ /get-drivers /format:table
Find the third-party storage driver in the list (published name oem##.inf), then remove it:
dism /image:C:\ /remove-driver /driver:oem12.inf
Windows falls back to its built-in driver on the next boot. Replace oem12.inf with the actual entry from the table.
Step 8: Roll Back From Safe Mode
If Windows will boot into Safe Mode, that is easier: Advanced options → Startup Settings → Restart → press 4. Then Device Manager → IDE ATA/ATAPI controllers or Storage controllers → Properties → Driver → Roll Back Driver. See how to enter Safe Mode.
What Not to Do
- Don't initialize or format the disk from another PC to "make it readable". Windows offering to initialize a drive it cannot mount is the fastest way to destroy the partition table and your data.
- Don't clean-install over the top before recovering files. The partition is almost always readable from another machine or a live USB.
- Don't change SATA mode back and forth repeatedly while BitLocker is active—each change costs another recovery-key entry.
Still Will Not Boot?
- Drive absent from BIOS entirely → reseat it, then test its health on another machine: check SSD or hard drive health.
- Everything else exhausted → recover your files first, then reinstall: reinstall Windows without losing data.
Drive readable but Windows will not load? RecoverPro can pull your files off the partition before you attempt any reinstall.
Related guides
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