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ArthurWu's avatar
ArthurWu
Iron Contributor
Oct 22, 2026

Windows 11 Error: UNMOUNTABLE_BOOT_VOLUME (0xED)

After turning on the computer, everything was working normally. I went to the kitchen, and when I came back, I found the computer was restarting. Then the UNMOUNTABLE_BOOT_VOLUME error (code 0xED) appeared, and the system booted into Safe Mode. I’ve tried several methods, but none of them worked.

Currently, I can access files using Notepad via the Command Prompt and have copied some folders to a USB drive. However, my goal is to restore Windows to a normal boot state without formatting the hard drive.

Please provide specific step-by-step instructions, explained in as simple and easy-to-understand terms as possible. Thank you.

 

Application Management
configuration

1 Reply

  • WinEndpointOps's avatar
    WinEndpointOps
    Tin Contributor
    Oct 22, 2026

    Good that you already copied your files off. UNMOUNTABLE_BOOT_VOLUME means Windows cannot read the system drive at startup, which is usually file system damage after an improper shutdown or restart, and sometimes a failing drive. You can try to repair it without formatting. In the Command Prompt you already have open (from Recovery or Safe Mode), do these in order:

     

    • First find the real Windows drive letter, because in recovery it is often D: instead of C:. Type dir D:\ and look for the Windows and Users folders. Use that letter below.
    • Check the drive for errors: chkdsk D: /f /r and press Enter (answer Y if it asks). This can take an hour or more on a large drive. Let it finish and do not turn the computer off.
    • Repair system files: sfc /scannow /offbootdir=D:\ /offwindir=D:\Windows
    • Repair the boot files: bootrec /scanos, then bootrec /rebuildbcd. If it says access denied or finds nothing, type bcdboot D:\Windows and restart.
    • Restart and see if Windows loads.

    If chkdsk reports a lot of bad sectors, or it stops or hangs, the drive itself is probably failing. In that case keep your files copied, and plan to replace the drive instead of repairing it. If the screen asks for a BitLocker recovery key at any point, you will need that key before any repair will work. You can find it by signing in to your Microsoft account on another device.