Understanding the Unmountable Boot Volume Error
When your computer crashes with a blue screen displaying “UNMOUNTABLE_BOOT_VOLUME” and the error code 0x000000ED, you’re facing one of the most serious boot-related errors in Windows. This specific Blue Screen of Death (BSOD) occurs when Windows cannot access the partition containing the operating system during the startup process.
Unlike many other blue screen errors, the Unmountable Boot Volume error directly prevents your computer from starting normally, making it particularly concerning because you cannot access your files or use your computer until the issue is resolved.
This comprehensive guide will walk you through understanding this critical error, recovering your data safely, and resolving the underlying issues to get your system working again.
What Causes the Unmountable Boot Volume BSOD Error?
Several factors can trigger this specific error code:
1. File System Corruption
Damage to the file system structure is a common cause:
– Corrupted Master File Table (MFT) in NTFS volumes
– Damaged file system metadata
– Boot sector corruption
– Partition table errors
2. Hard Drive or SSD Hardware Issues
Physical storage problems often trigger this error:
– Bad sectors on traditional hard drives
– Worn-out cells on SSDs
– Failing drive hardware
– Connection issues (loose or damaged cables)
– Power-related problems affecting the drive
3. Windows System File Corruption
Critical Windows files may be damaged:
– Corrupted system files are needed during boot
– Incomplete Windows updates
– Registry corruption affecting the boot process
– Boot Configuration Data (BCD) store damage
4. Driver Conflicts
Sometimes the issue is software-related:
– Incompatible storage drivers
– Corrupted disk controller drivers
– Driver conflicts after Windows updates
5. Improper System Shutdown
Unexpected power loss can cause this error:
– Power outages during disk write operations
– Forcing a shutdown while Windows is writing system files
– Battery depletion on laptops without proper hibernation
Immediate Actions When Facing Unmountable Boot Volume BSOD
When you encounter this error, follow these steps immediately:
1. Document the Complete Error Message
The blue screen often includes additional information that can help diagnose the specific cause:
– Note the complete error code (0x000000ED)
– Record any file names mentioned in the error
– Check for additional parameters or codes
2. Check Physical Connections
For desktop computers:
– Ensure all data and power cables to the hard drive are firmly connected
– Try different SATA ports on the motherboard
– Try different SATA or power cables if available
For laptops:
– Ensure the laptop hasn’t been dropped or subjected to physical shock
– If the drive is accessible (varies by model), check that it’s properly seated
3. Listen for Drive Sounds
For traditional hard drives:
– Normal sound: Steady, quiet humming
– Problematic sounds: Clicking, grinding, or no sound at all
Data Recovery Options for Unmountable Boot Volume BSOD
Method 1: Use Windows Recovery Environment
Windows includes built-in recovery tools:
1. Boot from Windows installation media or recovery drive
2. Select “Repair your computer” instead of “Install now”
3. Choose “Troubleshoot” > “Advanced options”
Try Automatic Repair/Startup Repair First
1. Select “Startup Repair” from Advanced options
2. Wait for the process to complete
3. Restart your computer to see if the issue is resolved
Use Command Prompt for Manual Repairs
If Startup Repair doesn’t work:
1. Select “Command Prompt” from Advanced options
2. Run CHKDSK to check and repair file system errors:
“`
chkdsk C: /f /r /x
“`
The parameters used:
– `/f` fixes errors on the disk
– `/r` locates bad sectors and recovers readable information
– `/x` forces the volume to dismount first if necessary
3. Repair the Master Boot Record and boot sector:
“`
bootrec /fixmbr
bootrec /fixboot
bootrec /rebuildbcd
“`
4. If you receive “The volume does not contain a recognized file system” error, try:
“`
diskpart
list volume
select volume C
exit
chkdsk C: /f /r
“`
Method 2: Use System Restore
If you have System Restore points configured:
1. Boot from Windows installation media or recovery drive
2. Select “Repair your computer” > “Troubleshoot” > “Advanced options”
3. Choose “System Restore”
4. Follow the prompts to restore to a point before the error occurred
Method 3: Data Recovery When Boot Repairs Fail
If you can’t repair the boot issue but need your data:
Option A: Use Command Prompt to Copy Files
1. Boot from Windows installation media or recovery drive
2. Select “Repair your computer” > “Troubleshoot” > “Command Prompt”
3. Identify your drives (system drive is often D: when booting from recovery media):
“`
diskpart
list volume
exit
“`
4. Create a backup folder on an external drive (e.g., E:):
“`
mkdir E:\Backup
“`
5. Copy your important files:
“`
xcopy D:\Users\YourUsername\Documents\*.* E:\Backup\Documents\ /s /e /h
“`
Repeat for other important folders (Desktop, Pictures, etc.)
Option B: Use a Live Linux USB
1. Create a bootable Linux USB drive (Ubuntu or Linux Mint work well)
2. Boot the affected computer from this USB
3. Linux will often mount NTFS partitions automatically
4. Browse to your data and copy it to an external drive
5. If the drive doesn’t mount automatically, use disk utility tools in Linux
Option C: Remove the Drive and Connect to Another Computer
1. Physically remove the drive from the affected computer
2. Connect it as a secondary drive to another computer using:
– Direct SATA connection
– USB adapter or enclosure
– Docking station
3. Browse and copy your important files
4. If the drive isn’t accessible directly, use data recovery software:
– Recuva
– TestDisk + PhotoRec
– R-Studio
– GetDataBack
Method 4: Create a Disk Image First (Recommended)
For the safest approach, especially with potentially failing drives:
1. Boot from a recovery environment (Windows PE, Linux, or specialized tools)
2. Use disk imaging software like DDRescue (Linux), Macrium Reflect, or FTK Imager
3. Create a sector-by-sector copy of the entire drive
4. Work with the image file rather than the original drive
5. Use recovery software on the image file
Example DDRescue command (Linux):
“`
ddrescue -d -r3 /dev/sda image.img logfile.log
“`
Method 5: Professional Data Recovery Services
Consider professional recovery when:
– The drive makes unusual noises
– The data is irreplaceable and highly valuable
– Multiple recovery attempts have failed
– The drive has physical damage
– You’re uncomfortable performing technical procedures
Professional services offer:
– Clean room environments for physical drive repair
– Specialized equipment for reading damaged media
– Proprietary techniques for severe cases
– Higher success rates for critical recoveries
Fixing Unmountable Boot Volume After Data Recovery
Once your data is safely recovered, address the underlying issues:
1. Check for Drive Health Issues
Before attempting repairs, verify the drive’s condition:
1. Boot from recovery media
2. Open Command Prompt
3. Run `wmic diskdrive get status,model` to check basic drive status
4. For more detailed analysis, use manufacturer diagnostic tools from a working computer:
– SeaTools for Seagate drives
– Data Lifeguard for Western Digital
– SSD Life for solid state drives
5. Check S.M.A.R.T. attributes using CrystalDiskInfo from another computer
2. Repair Windows Without Reinstalling
If the drive is healthy, try these repair options:
Option A: Rebuild BCD Store
1. Boot from Windows installation media
2. Open Command Prompt from recovery options
3. Run these commands:
“`
bootrec /rebuildbcd
bcdboot C:\Windows /s C:
“`
Option B: Use DISM and SFC
1. Boot from Windows installation media
2. Open Command Prompt from recovery options
3. Run DISM to repair the Windows image:
“`
DISM /Image:C:\ /Cleanup-Image /RestoreHealth
“`
4. Run System File Checker:
“`
sfc /scannow /offbootdir=C:\ /offwindir=C:\Windows
“`
3. Reinstall Windows While Preserving Data
If repairs don’t work but the drive is healthy:
1. Boot from Windows installation media
2. Choose “Install now”
3. Select “Custom: Install Windows only”
4. Select your existing Windows partition
5. Click “Format” (ensure your data is backed up first)
6. Complete the installation process
7. Restore your data from backups
4. Replace the Hard Drive if Necessary
If diagnostics show drive failure:
1. Purchase a compatible replacement drive
2. For traditional hard drives, match or exceed:
– Form factor (3.5″ for desktops, 2.5″ for laptops)
– Interface type (SATA, IDE, etc.)
– Capacity
3. For SSDs, match:
– Form factor (2.5″ or M.2)
– Interface (SATA or NVMe)
– Connection type (M.2 drives come in different keying configurations)
4. Install Windows on the new drive
5. Restore your data from backups
Preventing Future Unmountable Boot Volume Errors
Implement these preventive measures to avoid future instances:
1. Regular Backups
– Follow the 3-2-1 backup rule (3 copies, 2 different media types, 1 off-site)
– Automate backups with Windows Backup or third-party tools
– Verify backups regularly by testing restoration
2. Monitor Drive Health
– Install S.M.A.R.T. monitoring software like CrystalDiskInfo
– Schedule regular disk checks
– Replace drives showing early warning signs
– Most drives last 3-5 years; plan for replacement
3. Proper System Maintenance
– Keep Windows updated
– Use a UPS (Uninterruptible Power Supply) to prevent power-related damage
– Shut down properly instead of forcing power off
– Run CHKDSK periodically: `chkdsk C: /f`
4. Create Recovery Media
– Make Windows recovery drives while your system is healthy
– Keep installation media accessible
– Create a bootable Linux USB for emergency data recovery
Troubleshooting Specific Unmountable Boot Volume Scenarios
Scenario 1: Error After Windows Update
If the error appears after a Windows update:
1. Boot to the recovery environment
2. Select “Troubleshoot” > “Advanced options” > “System Restore”
3. Choose a restore point before the update
4. Complete the restoration process
If System Restore isn’t available:
1. Use the Command Prompt from the recovery environment
2. Try the DISM and SFC commands mentioned earlier
3. If unsuccessful, consider rolling back the update using:
“`
dism /image:C:\ /get-packages
dism /image:C:\ /remove-package /packagename:PackageNameFromList
“`
Scenario 2: Error After Hardware Changes
If the error appears after adding or changing hardware:
1. Restore the original hardware configuration if possible
2. Reset BIOS/UEFI to default settings
3. Check if drive mode changed (AHCI vs. IDE mode in BIOS)
4. If you added a new drive, ensure the boot order is correct
Scenario 3: Error After Power Loss
If a power outage caused the issue:
1. Try Startup Repair first
2. Run CHKDSK with all repair options
3. If unsuccessful, use the bootrec commands
4. Consider investing in a UPS to prevent future issues
Scenario 4: Intermittent Boot Failures
If the error occurs occasionally:
1. Check for loose connections
2. Test the power supply
3. Monitor drive temperature
4. Run extended drive diagnostics
5. Consider replacing the drive even if it passes basic tests
Advanced Troubleshooting for Unmountable Boot Volume BSOD
Technique 1: Analyze Boot Configuration Data
For advanced users comfortable with BCD manipulation:
1. Boot from recovery media
2. Open Command Prompt
3. Export the current BCD for backup:
“`
bcdedit /export C:\BCD_Backup
“`
4. Rebuild it from scratch:
“`
bootrec /rebuildbcd
“`
5. If that fails, manually recreate it:
“`
bcdedit /create {bootmgr} /d “Windows Boot Manager”
bcdedit /create {ntldr} /d “Windows Legacy OS Loader”
bcdedit /set {bootmgr} device partition=C:
bcdedit /set {bootmgr} path \bootmgr
bcdedit /set {ntldr} device partition=C:
bcdedit /set {ntldr} path \ntldr
bcdedit /displayorder {ntldr} /addlast
“`
Technique 2: Check for File System Conversion Issues
Sometimes the error occurs after converting between file systems:
1. Boot from recovery media
2. Open Command Prompt
3. Check the file system type:
“`
fsutil fsinfo volumeinfo C:
“`
4. If it shows RAW instead of NTFS, the file system is severely corrupted
5. Try TestDisk to recover the partition table and file system
Technique 3: Disable Early Launch Anti-Malware
Some anti-malware drivers can cause boot issues:
1. Boot from recovery media
2. Open Command Prompt
3. Load the registry:
“`
reg load HKLM\TEMP C:\Windows\System32\config\SYSTEM
“`
4. Disable Early Launch Anti-Malware:
“`
reg add “HKLM\TEMP\ControlSet001\Control\DeviceGuard\Scenarios\HypervisorEnforcedCodeIntegrity” /v “Enabled” /t REG_DWORD /d 0 /f
“`
5. Unload the registry:
“`
reg unload HKLM\TEMP
“`
6. Restart and check if the issue is resolved
Technique 4: Check for Disk Signature Collisions
Multiple drives with the same signature can cause boot issues:
1. Boot from recovery media
2. Open Command Prompt
3. Run diskpart:
“`
diskpart
list disk
Select disk 0
uniqueid disk
“`
4. Note the disk signature
5. Check other disks for the same signature
6. If found, change one of them:
“`
uniqueid disk id=UniqueIDHere
“`
Conclusion
The Unmountable Boot Volume BSOD (0x000000ED) is a serious error that prevents Windows from starting normally. While it can be alarming, with the right approach, you can often recover your data and fix the underlying issues.
Remember that this error is frequently a warning sign of potential hardware failure or significant system corruption, so taking immediate action is crucial. By understanding the causes and solutions for this specific blue screen error, you’re now equipped to handle it effectively and protect your valuable data.
After experiencing this error, it’s wise to be proactive about checking drive health and implementing a robust backup strategy. Regular maintenance and safe computing practices can help prevent future occurrences of this and similar errors.
Have you successfully resolved an Unmountable Boot Volume BSOD? Share your experience in the comments below to help others facing similar challenges. Know About How to Recover Unsaved Word Documents
