INACCESSIBLE_BOOT_DEVICE: Windows 11 & 10 Fix (Updated)

If your PC won't boot and shows INACCESSIBLE_BOOT_DEVICE, the fastest fix in most cases is a BIOS storage-mode check followed by a Startup Repair from the Windows Recovery Environment — not a reinstall. Most PCs showing this error still have every file intact; the drive itself is usually fine. What's broken is Windows' ability to talk to it at the moment it tries to boot, and that's a narrower, more fixable problem than the all-caps error screen makes it look.

Jake's first customer of the week brought in a laptop that had been fine on Friday and wouldn't get past a blue screen on Monday. No new hardware, no dropped laptop, nothing anyone in the house would admit to changing. That's the ordinary shape of this error, and it's worth saying up front: this is not always someone's fault.

What INACCESSIBLE_BOOT_DEVICE Actually Means

The name is more alarming than the problem, so let's take it apart. Windows starts up in stages: firmware finds the drive, a small boot loader hands off to Windows itself, and very early in that handoff Windows loads the driver for whatever is controlling your storage — usually a SATA or NVMe controller. INACCESSIBLE_BOOT_DEVICE means Windows got far enough to look for that driver and either couldn't find one that matched, or found one it didn't trust. It is not the same thing as "the hard drive is dead," even though it can look identical from the screen you're staring at.

Ethan's rule for this error: "Never open the case before you've checked the BIOS and run a repair. I've seen people replace an SSD that was perfectly healthy because they assumed the worst-case explanation first." The all-caps error text is designed to look catastrophic. Most of the time it's a mismatch, not a death sentence.

The One Question That Tells You Which Fix to Try First

Did anything change right before this started? A Windows update, a BIOS setting, new hardware, a dropped or bumped laptop, or a power outage mid-update. Your answer sends you down one of two routes, and it's the single most useful thing you can figure out before touching anything else.

"Yes, something changed" → the software route

If you can point to a specific update, setting, or piece of hardware, the fix is almost always software-side: undo the BIOS change, roll back the driver, or repair the boot files that got scrambled mid-update. This is the fast path and it doesn't touch your data.

"No, nothing changed" → the hardware route

If the PC has been sitting untouched and simply refused to boot one morning, that shifts the odds toward a genuinely failing drive or a loose connection — still fixable, and still not automatically a data-loss event, but you'll want to prioritize getting your files off before you do anything invasive.

Fixing It on Windows 11

Step 1: Get into the Windows Recovery Environment

You need to reach a screen called the Windows Recovery Environment, or WinRE — a separate, minimal version of Windows that runs even when your main installation won't boot. There are three ways in:

• If Windows can show you a sign-in screen, click the power icon, hold Shift, and click Restart.
• If the PC fails to boot three times in a row, Windows 11 will drop into WinRE automatically and show "Preparing Automatic Repair."
• If neither works, boot from a Windows 11 installation USB, pick your language, and look for Repair your computer in the small text at the bottom-left of the setup screen — easy to miss, and the only way in if the PC won't start Windows at all.

Step 2: Check the BIOS storage mode first

Before running anything, restart into your BIOS/UEFI setup (usually a key like F2, F10, F12, or Delete right after power-on — it varies by manufacturer) and look for a setting called SATA Mode, Storage Configuration, or similar. If it's set to RAID and you don't actually use a RAID array, or if it was recently switched from AHCI, switch it back to whatever it was when Windows was first installed. This single check resolves a large share of INACCESSIBLE_BOOT_DEVICE cases, particularly on PCs where a BIOS update reset custom settings back to a default that doesn't match how Windows was installed.

Step 3: Run Startup Repair

From WinRE: Troubleshoot → Advanced options → Startup Repair. It scans for common boot problems and fixes what it can automatically. It fails silently more often than it should, but it's non-destructive, so there's no reason to skip it.

Step 4: Rebuild the boot files manually

If Startup Repair gives up, open Troubleshoot → Advanced options → Command Prompt and run these one at a time:

• chkdsk c: /f /r — checks the drive for file-system errors and bad sectors. This can take a long time on a large or aging drive; let it finish.
• bootrec /fixmbr — repairs the master boot record.
• bootrec /fixboot — repairs the boot sector.
• bootrec /scanos — looks for installed Windows copies the boot menu doesn't currently know about.
• bootrec /rebuildbcd — rebuilds the Boot Configuration Data, the file that tells your PC which Windows installation to start and how.

Restart after each pair of commands rather than running all five blind — it's slower, but it tells you which one actually mattered if the PC comes back up.

Step 5: Roll back the driver, if that's what changed

If this started right after a Windows update, the update may have installed a storage driver your controller doesn't get along with. From WinRE's command prompt, or from Device Manager if you can get that far, rolling back to the previous driver version resolves this more often than a full driver reinstall does.

Fixing It on Windows 10

These steps are the same as Windows 11 once you're inside WinRE — chkdsk, bootrec, driver rollback all work identically. What differs is getting there.

Getting into recovery on Windows 10

• Hold Shift and click Restart from the sign-in screen power icon — identical to Windows 11.
• Three failed boots in a row also triggers Automatic Repair automatically, same as Windows 11.
• From installation media, choose Repair your computer at the bottom-left of the first setup screen.

Follow Steps 2 through 5 above exactly as written — BIOS check, Startup Repair, the chkdsk/bootrec sequence, then driver rollback if a recent update is the suspect.

If Nothing Changed: Check the Hardware

If you answered "no" to the diagnostic question earlier, work through these before assuming the worst:

• Reseat the drive connection. On a desktop, power down fully, open the case, and check that the SATA and power cables are firmly seated at both ends. A cable that's 90% connected can produce exactly this error intermittently.
• Try a different SATA port and cable if you have spares. This rules out a failing port or cable rather than the drive itself.
• Check if the drive even shows up in the BIOS. If your BIOS's boot menu or storage page doesn't list the drive at all, that points much more strongly toward drive failure than a driver mismatch.
• Listen for it, on a mechanical hard drive. Repeated clicking or grinding on spin-up is a hardware failure sign, not a boot-configuration one. SSDs won't give you this audio cue, which is part of why they can fail more quietly.

When None of That Works

You can't reach WinRE at all

Create Windows installation media on a working PC (Microsoft's own tool for this is free), boot the broken PC from that USB, and use "Repair your computer" from the first setup screen. This gets you into WinRE even when the internal recovery partition itself is damaged.

Startup Repair says it couldn't fix the problem

That message just means the automated scan didn't recognize the specific fault — it doesn't mean the manual chkdsk/bootrec sequence above won't work. Go through Step 4 by hand before concluding the PC is unrecoverable.

Dual-boot or a second Linux drive is involved

If bootrec /rebuildbcd reports finding zero or multiple Windows installations unexpectedly, a second OS on another drive may be interfering with the boot order. Disconnect other internal drives temporarily, run the repair against Windows alone, then reconnect once it boots.

Nothing above works and the drive isn't detected anywhere

At that point, treat it as a hardware failure. Your priority shifts from "get it booting" to "get the files off," which usually means removing the drive and connecting it to another PC as a secondary disk, or via a USB enclosure. If the drive won't even mount that way, that's the point where dedicated data-recovery services are worth pricing out rather than continuing to troubleshoot.

Edge Cases: Laptops, VMs, and External Drives

Laptops with no visible BIOS key prompt

Some thin-and-light laptops boot too fast to catch a function-key prompt, or don't show one at all. If Windows will boot even occasionally, get into WinRE first via Shift+Restart, then reach UEFI settings from there: Troubleshoot → Advanced options → UEFI Firmware Settings. On Surface-style devices with no F-key row, holding the volume-up button while pressing power gets you into firmware setup directly.

Virtual machines

The same error shows up inside VMs, and the usual trigger is different: changing the virtual disk controller type — IDE to SCSI, or SATA to NVMe — in the VM's settings after Windows was already installed against the old controller. If you recently edited a VM's hardware configuration, that's the first thing to revert, before you touch anything inside the guest OS itself.

Booting from a cloned or external drive

If Windows was cloned onto a new internal drive, or you're booting Windows from an external USB enclosure, this error often means the clone didn't carry over the right storage driver for the new hardware, or the boot order is pointing at a drive that was never meant to fully boot an OS. Re-cloning with drive-specific driver injection, or moving back to the original drive to confirm the OS itself is intact, narrows this down fast.

If You End Up Reinstalling

Before you do:

• If Windows still boots into WinRE even though it won't boot normally, you may be able to pull files off via the command prompt's file-copy tools onto a USB drive first.
• If the drive mounts on another PC, copy your files there before doing anything else.
• "Reset this PC → Keep my files" in WinRE is a middle ground between a repair and a full reinstall — it reinstalls Windows but attempts to preserve your personal files. Treat "attempts to preserve" as exactly that, not a guarantee, and back up first if you have any way to.

Frequently Asked Questions

Will I lose my files fixing this?

Not from any of the steps in the software-fix sections — chkdsk, bootrec, driver rollback, and Startup Repair all leave your personal files alone. Risk to your files only enters the picture with a full reset or reinstall, and even then "Keep my files" is designed to preserve them.

Why did this happen right after a Windows update?

Updates occasionally install a storage driver that doesn't match your specific controller, or the update process itself can be interrupted by a power loss or forced restart at exactly the wrong moment, leaving the boot files half-written.

Why did this happen after I changed a BIOS setting?

Windows loads a specific storage driver at boot based on how the drive was configured when Windows was installed. Switching the SATA mode afterward — AHCI to RAID, for instance — means Windows tries to use a driver that no longer matches, and the boot fails at exactly the step this error describes.

Can I fix this without a USB installation drive?

Yes, in most cases. Both the Shift+Restart method and the automatic three-failed-boots trigger get you into WinRE using tools already on your PC. You only need installation media if the recovery partition itself is damaged or missing.

What if Startup Repair says it couldn't repair my PC?

That's a common outcome, not a dead end. Move on to the manual chkdsk and bootrec sequence — it catches a number of cases the automated scan doesn't recognize.

What if my drive isn't showing up at all, even in the BIOS?

That points toward a connection or hardware problem rather than a boot-configuration one. Reseat the cables on a desktop, or try the drive in another machine, before assuming total failure.

Is this the same as a boot error with a different stop code?

INACCESSIBLE_BOOT_DEVICE is its own named stop error with its own boot-time cause — a driver or boot-configuration problem specifically at the storage-access stage. Other blue-screen stop codes point to different subsystems entirely, so the fixes here are specific to this one, not a general BSOD checklist.

Can a failing drive cause this with no recent changes at all?

Yes. Drives, especially aging mechanical ones, can develop faults gradually and then fail at a boot-critical moment with no obvious trigger. That's exactly why the diagnostic question at the top of this post matters — "nothing changed" genuinely shifts the odds toward hardware.

What's the difference between bootrec /fixboot and /rebuildbcd?

/fixboot repairs the boot sector on the drive itself. /rebuildbcd rebuilds the Boot Configuration Data that lists which Windows installations exist and how to start them. Run them in the order given above; they fix different, adjacent problems.

Do I need to reinstall Windows to fix this?

Rarely. It's the last item on this page for a reason — most cases resolve at the BIOS-check, Startup Repair, or bootrec stage without touching your installed copy of Windows at all.

Can I recover files if I do end up resetting or reinstalling?

If the drive is still readable — which it usually is with this specific error — pull your files off first, either through WinRE's command prompt or by connecting the drive to another PC, before you reset or reinstall.

Is this more common on Windows 11 or Windows 10?

The underlying causes — driver mismatches, BIOS storage-mode changes, boot file corruption, failing drives — aren't tied to a specific Windows version. What changes between the two is only how you reach the recovery tools, which is why we've split those steps out above.

Does being past Windows 10's end of support make this worse?

Not for this specific error — the fix steps are identical whether or not you're enrolled in Extended Security Updates. It's worth knowing ESU enrollment is still open and now runs through October 2027, in case a boot failure has you weighing repair against replacement.

How do I know it's safe to leave the BIOS setting switched back?

If switching the SATA/storage mode back to its original value is what got you booting again, leave it there. Changing it again later without a specific reason to reinstates the same mismatch that caused this in the first place.

Can malware or antivirus software cause this error?

It's possible for malware that tampers with boot files to produce a similar symptom, though it's a less common cause than driver mismatches or BIOS changes. If none of the fixes above work and you have reason to suspect an infection, that's worth investigating separately before you reinstall.

Revision note. Originally published August 22, 2015, when this error was showing up on brand-new Windows 10 installs. INACCESSIBLE_BOOT_DEVICE is its own named stop error, not tied to that code. Rewritten today for Windows 11 and Windows 10, with the recovery-environment steps updated to match how both versions actually look now, and a note for anyone still running Windows 10 past its October 2025 end of support. If you're staring at this screen right now with a PC that won't boot, take a breath — in our experience this looks far worse than it usually turns out to be, and there's a good chance you'll have it running again before you finish your coffee.