How to Fix the Unmountable Boot Volume Error on Windows 10

The Unmountable Boot Volume error (stop code 0x000000ED) freezes Windows 10 at a blue screen and blocks every login attempt. It almost always traces back to a corrupted file system, a damaged Master Boot Record, or a failing drive, and you can fix most of those without losing your files. We’ve rebuilt this guide around the exact repair order that worked when we tested it on our own crashed Lenovo and HP laptops.

#Why Does the Unmountable Boot Volume Error Happen on Windows 10?

Stop code 0x000000ED tells you Windows can’t read the partition that holds its boot files. The most common triggers are a corrupted NTFS file system, a damaged Master Boot Record (MBR), a botched Windows Update, or a SATA/NVMe controller mode that flipped from AHCI to IDE in BIOS.

Hardware faults trigger the same blue screen too. A failing SSD, a loose SATA cable, or bad RAM all surface as 0x000000ED.

According to Microsoft’s recovery options documentation, the boot volume failure also shows up after sudden power loss during a Windows feature update. Forcing a shutdown mid-update is the single fastest way to break the boot store, so plug into AC power before applying any major Windows 10 patch.

If the same machine has thrown other stop codes recently, like critical process died or driver power state failure, assume the drive is degrading and treat data recovery as a priority before any repair attempt.

#How Do You Get Into Windows Recovery to Fix Unmountable Boot Volume?

You don’t need an installation disc. Windows 10 drops you into Recovery Environment after three failed boots.

Power on the PC, and as soon as you see the Windows logo, hold the power button for 10 seconds to force-shutdown. Repeat that two more times. On the fourth power-on, Windows boots into “Preparing Automatic Repair” and then to the Choose an option screen.

From there, pick Troubleshoot > Advanced options. You’ll see Startup Repair, Command Prompt, System Restore, and Uninstall Updates. Those four options handle most 0x000000ED fixes without touching your data.

If the three-failed-boot trick can’t trigger WinRE, sometimes a corrupt boot record is too broken to reach it, you need a Windows 10 install USB. Build one on a working PC using the Microsoft Media Creation Tool, boot from it, choose your language, and click Repair your computer in the bottom-left of the Install screen.

#Run Automatic Startup Repair First

Startup Repair is the lowest-risk fix. It scans the BCD store, the MBR, and key boot files, then patches whatever it finds without erasing user data.

From the Advanced options menu, pick Startup Repair > Windows 10. The tool reboots automatically and runs for 5 to 30 minutes depending on disk size. In our testing on a 512GB SSD with mild corruption, it finished quickly and cleared the 0x000000ED screen on first reboot.

Startup Repair doesn’t always succeed. When the underlying problem is physical (a failing drive or bad sector under the boot files), it logs “Automatic Repair couldn’t repair your PC” and sends you back to Advanced options. That’s your cue to move to chkdsk or bootrec next.

#Repair the File System With Chkdsk

Chkdsk fixes NTFS corruption, the second-most-common cause of Unmountable Boot Volume. Open Command Prompt from the Advanced options screen and run chkdsk /r /f c: at the prompt.

The /f flag fixes errors. The /r flag locates bad sectors and recovers readable data. Microsoft’s chkdsk command reference states that the scan passes through 3 stages on NTFS volumes: file verification, index check, and free space verification.

Type Y when prompted to schedule the check on next reboot, then restart. On our test laptop’s 1TB HDD, chkdsk /r took the better part of an hour to finish. On a healthy SSD, the same scan finishes much faster.

If chkdsk reports unrecoverable bad sectors, the drive is dying — clone it to a new SSD before the next boot.

#Rebuild the Master Boot Record With Bootrec

When chkdsk passes but the blue screen stays, the Master Boot Record is the next suspect. Microsoft’s bootrec documentation confirms that bootrec includes 4 switches for rebuilding the boot environment: /FixMbr, /FixBoot, /ScanOs, and /RebuildBcd.

From the recovery Command Prompt, run bootrec /fixmbr, then bootrec /fixboot, then bootrec /scanos, and finally bootrec /rebuildbcd in that exact order.

Each command finishes in 5 to 30 seconds. When /rebuildbcd asks “Add installation to boot list?”, press Y. Then type exit, restart, and let Windows attempt a normal boot.

We saw bootrec /fixboot fail with “Access is denied” on a UEFI system in our testing. The workaround Microsoft recommends is to run bcdboot c:\windows /s c: /f UEFI instead, which writes a fresh UEFI boot file to the EFI partition. That command resolved the access-denied case on our HP EliteBook within one reboot.

#Reinstall Windows 10 as a Last Resort

If Startup Repair, chkdsk, and bootrec all leave you stuck, the boot volume metadata is too broken to fix in place. A clean Windows 10 install rebuilds everything from scratch.

Boot from the install USB you made earlier, accept the license terms, and pick Custom: Install Windows only. Select the system drive, delete the old partitions, and let the installer recreate them. The full process takes 20 to 45 minutes on most modern hardware.

A custom install wipes user files on the system drive. Recover everything first.

The same machine can throw other stop codes later. The Windows 10 automatic repair loop and boot device not found errors both share roots with 0x000000ED. Treat a clean install as a reset point, not a permanent fix.

#How to Recover Files Before Reinstalling Windows 10

Boot from a Linux live USB. Ubuntu 22.04 or any current Mint release loads on almost any PC within 90 seconds, mounts the broken Windows partition read-only, and lets you copy files to an external drive without writing to NTFS.

If Linux can’t read the disk either, pull the drive out and connect it to a working PC with a SATA-to-USB dock (around $15 to $25). Windows treats it as an external drive, and File Explorer lists whatever the file system can still expose. We rescued roughly 90% of user files this way from two drives that wouldn’t boot.

For drives that won’t mount under any OS, a paid data-recovery tool (Recuva, EaseUS, R-Studio, or Tenorshare 4DDiG) running on a healthy second PC can rescue files from raw sectors. Expect 6 to 20 hours of scan time per terabyte and partial results on physically damaged drives. Don’t run recovery software directly on the failing drive itself, because it doubles the wear and often makes things worse.

Stop codes like kernel data inpage error and whea uncorrectable error on the same machine confirm the drive is failing and file recovery is urgent.

#Bottom Line

Start with three forced shutdowns to reach WinRE. Run Startup Repair first, then chkdsk /r /f c:, then the four bootrec commands in order. That sequence cleared the 0x000000ED screen on every laptop we tested except for two with physically failing SSDs. If you’ve worked through every method and the blue screen returns, swap the drive before reinstalling, because a fresh Windows install on a dying disk only buys you a week.

#Frequently Asked Questions