How to Fix UNMOUNTABLE BOOT VOLUME Error in Windows 10

The UNMOUNTABLE BOOT VOLUME error in Windows 10 usually appears as a Blue Screen of Death (BSOD) and indicates issues with the boot volume. In this guide, we will explain the common causes of this error and provide step-by-step solutions to fix it.

What Does UNMOUNTABLE BOOT VOLUME Mean?

The UNMOUNTABLE BOOT VOLUME error means that Windows cannot access the boot partition of your hard drive or SSD. This can be caused by:

  • Corrupted system files;
  • File system errors (e.g., corrupted NTFS);
  • Hard drive or SSD failures;
  • Sudden power loss or improper shutdown;
  • Incorrect BIOS or UEFI settings (e.g., incorrect SATA Mode);
  • Faulty or incomplete Windows updates.

Methods to Fix UNMOUNTABLE BOOT VOLUME Error

There are several ways to resolve this issue, ranging from simple checks to more advanced system repairs. Follow these methods in the order listed.

1. Restart Your Computer

Sometimes a simple reboot can resolve the issue. If this doesn’t help, move on to the next method.

2. Use System Restore

Try booting into the Windows Recovery Environment:

  1. Restart your computer and press F8 or Shift + F8 before the Windows logo appears.
  2. Select Troubleshoot → Advanced options → System Restore.
  3. Follow the on-screen instructions to restore your system to a previous state.

3. Run CHKDSK Command

The CHKDSK command checks your disk for errors and repairs them. To use it, follow these steps:

  1. Boot from a Windows 10 installation media or enter the Recovery Mode.
  2. Open the Command Prompt and type the following command:
chkdsk /f /r C:

After the scan completes, reboot your system.

4. Repair Boot Files

If the error persists, it could be due to corrupted boot files. Enter these commands in the Command Prompt to repair them:

bootrec /fixmbr
bootrec /fixboot
bootrec /scanos
bootrec /rebuildbcd

These commands will help rebuild the master boot record and other critical boot files.

5. Check BIOS/UEFI Settings

In some cases, the issue is related to incorrect BIOS/UEFI settings. Ensure that the SATA Mode is set correctly (either AHCI or IDE).

  1. Restart your computer and enter BIOS/UEFI by pressing F2, Del, or Esc during boot.
  2. Navigate to the Storage or Advanced tab and check the SATA Mode setting.
  3. Set it to AHCI or IDE if it’s different.
  4. Save changes and restart your computer.

6. Reinstall Windows

If none of the above methods work, you may need to reinstall Windows 10. Before doing so, ensure you back up all important data.