UNMOUNTABLE_BOOT_VOLUME (0x000000ED): Windows Blue Screen Fix

Quick answer

The Windows stop code UNMOUNTABLE_BOOT_VOLUME (0x000000ED) means: Windows could not mount the startup drive. This code often points to hardware, disk or startup problems. Back up important files as soon as you can and follow the steps below; if it keeps returning, have the PC checked.

Before you start: note the stop code shown on the blue screen. If Windows will not start normally, it usually opens Automatic Repair after two failed starts; from there choose Advanced options to reach Safe Mode or System Restore.

Is it serious? Can I keep using my PC?

Severity: High

This code often points to hardware, disk or startup problems. Back up important files as soon as you can and follow the steps below; if it keeps returning, have the PC checked.

Common causes

Failing or corrupted disk or SSD
Corrupted file system or Windows system files
Storage controller setting changed (AHCI/RAID) or missing storage driver

How to fix it

Restart the PC. If the blue screen happened only once and does not return, no further action is usually needed
Check the disk with "chkdsk C: /f" and check the drive's health
Make sure the BIOS storage mode (AHCI/RAID/VMD) was not changed and the storage driver is installed
Use System Restore or uninstall the latest Windows update from Advanced startup

Frequently asked questions

What does UNMOUNTABLE_BOOT_VOLUME mean?

The Windows stop code UNMOUNTABLE_BOOT_VOLUME (0x000000ED) means: Windows could not mount the startup drive.

Is UNMOUNTABLE_BOOT_VOLUME serious?

Severity: High. This code often points to hardware, disk or startup problems. Back up important files as soon as you can and follow the steps below; if it keeps returning, have the PC checked.

How do I fix UNMOUNTABLE_BOOT_VOLUME?

Start with these steps: Restart the PC. If the blue screen happened only once and does not return, no further action is usually needed; Check the disk with "chkdsk C: /f" and check the drive's health; Make sure the BIOS storage mode (AHCI/RAID/VMD) was not changed and the storage driver is installed; Use System Restore or uninstall the latest Windows update from Advanced startup.

Related codes

0x24 NTFS_FILE_SYSTEMA problem occurred in the NTFS file system driver, usually because of disk or file system corruption.0xF4 CRITICAL_OBJECT_TERMINATIONA process or thread essential to Windows ended unexpectedly.0x77 KERNEL_STACK_INPAGE_ERRORWindows could not read kernel data from the page file into memory, usually because of a disk problem or faulty RAM.0x7A KERNEL_DATA_INPAGE_ERRORWindows could not read a page of kernel data into memory, usually because of a disk, cable or RAM problem.0x7B INACCESSIBLE_BOOT_DEVICEWindows lost access to the system drive during startup.0xEF CRITICAL_PROCESS_DIEDA process that Windows needs to run stopped unexpectedly.0x154 UNEXPECTED_STORE_EXCEPTIONThe memory store component hit an unexpected error, often linked to the disk or security software.0x19 BAD_POOL_HEADERThe memory pool used by Windows has become corrupted, usually by a faulty driver.0x1A MEMORY_MANAGEMENTA serious memory management error occurred, often caused by faulty RAM or a driver.