How to fix UNMOUNTABLE_BOOT_VOLUME on Windows 10

Getting Windows 10 UNMOUNTABLE_BOOT_VOLUME BSOD loop at startup?

Laptop won’t start after a Windows 10 feature update. Frequently getting Unmountable Boot Volume?

You are on the right place here, this post we have different solutions to fix Unmountable Boot Volume BSOD on Windows 10.

Issue: After Windows 10 upgrade getting unmountable boot volume BSOD

I recently upgraded six client Windows 10 v1809 computers to Windows 10 v2004 via WSUS, when the computers restarted I got the BSOD error unmountable boot volume stop 0x000000.

Unmountable Boot Volume Error? The “boot volume” is the system partition of your hard drive that holds the Windows operating system. But If due to any reason when your computer can’t load Windows properly from the system partition this will result startup failure with a BSOD error “UNMOUNTABLE_BOOT_VOLUME” stop 0x000000

Unmountable Boot Volume error usually occurs due to a damaged file system or corrupted Windows files. Again Window update bug, disk drive failure, security software or faulty hardware device or incompatible device driver also cause this Windows 10 BSOD error. Whatever the reason, here some solutions you may apply to fix this Blue Screen error.

Whenever you get windows 10 Blue Screen error at startup, The first thing you have to do is disconnect all external devices such as a printer, scanner, external HDD, USB device etc ( expect keyboard&mouse) then start windows normally.Use Windows Automatic Repair

As we are unable to start access windows 10 normally, we need to access advanced options where you can get various troubleshooting tools like startup repair, safe mode, advanced command prompt and more. Lets first access advanced options and perform startup repair.

• First of all boot windows from an installation media, (If you don’t have here check how to create a windows 10 bootable USB/DVD).

• Let Windows start from your USB/DVD until it loads up, and click the next button.

• You’ll see the Install now screen click repair your computer in the bottom-left instead.

• On the following screen, select troubleshoot to get a list of advanced options.

• Choose startup repair and choose the target OS, Windows 10 (or your version).

• The repair will be started immediately.

• Please wait patiently for the process to be finished.

Once it’s done, exit the installer and try to boot your computer normally.

Repair the Master Boot Record

The Master Boot Record (MBR) contains information about where and how your operating system is located your hard drive and helps it load properly when you turn your computer on. If this becomes corrupted, it can lead to an unmountable boot volume error.

• Again access advanced options from your Windows 10 install media

• Select repair your computer > troubleshoot.

• This time, on the advanced options screen, choose command prompt.

Perform command below to repair MBR, rebuild BCD and fix boot manager problems

• bootrec /fixmbr

• bootrec /fixboot

• bootrec /rebuildbcd

• bootrec /scanos

• After complete these commands type exit to leave the command prompt,

• Then reboot your system and check this time windows started normally

Run the Ckhdsk Command

If an automatic repair and MBR repair didn’t solve your problem, then boot into safe mode from advanced options and run Chkdsk command to check and fix disk drive errors.

• When windows start on safe mode search for cmd,

• Right click on the command prompt and select run as administrator.

• Then type command chkdsk C: /f /r

Note: Here C: is your system drive letter. The /r flag locates any bad sectors on your disk and fixes those errors and /f Fixes errors on the disk.

• Chkdsk may ask you to run next time the system restarts.

• If it does, enter Y for yes and reboot to start it.

• This will start the scanning and repairing process for drive C:

• Wait until 100% complete the scanning process

• After that restart windows and check may this helps to fix the windows 10 BSOD error.

Run SFC utility and DISM command

Run system file checker its another effective solution (scan and restore missing corrupted system files ) you must apply if windows fail to fix unmountable boot volume after applying startup repair, repair BCD/MBR, check drive errors.

• Again open the command prompt (admin) on safe mode

• Type command sfc /scannow and hit the enter key.

• This will scan for corrupted system files If found any the SFC utility will restore them from a special folder located on %WinDir%\System32\dllcache.

• Wait until 100% complete the scanning process

• After that restart windows and check, You never get a BSOD error if missing corrupted system files causing the issue.

If system file checker scan results windows resource protection found corrupt files but was unable to fix some of them. Then run the DISM command “dism.exe /online /cleanup-image /restorehealth” which repair the system image and allow SFC to do its job.

Run Memory Diagnostic Tool

Sometimes this Unmountable Boot Volume Blue Screen STOP: 0x000000ED can happen due to bad memory so for this try Run Memory Diagnostic Tool.

Run the Hardware and Device troubleshooter from settings -> update & Security -> Troubleshoot -> select Hardware and Device and run the Troubleshooter for check and make sure any faulty hardware device not causing the BSOD error at startup.

Also Recently installed Third-party applications to check and make sure application compatibility not causing the issue. Open Control Panel -> All Control Panel Items -> Programs and Features. Here select the recently installed Application and click uninstall Restart windows and check.

Open device manager and update/reinstall the display driver with the latest version. As users report reinstall the display driver mostly fix maximum blue screen errors on windows 10.

If the problem started for you after installing windows 10 version 1903 and applying the above these solutions didn’t fix the problem then may the windows update bug causing the issue. As Microsoft recommends Roll back windows 10 to the previous version, Defer windows update and wait for Microsoft to fix the bug and the OS get stable.

Performing the above solution didn’t fix the problem, Still, windows restart with BSOD error then its time to utilize the system restore feature, which reverts windows configuration to a previous working state without affecting any files.

Did these solutions help to resolve Unmountable Boot Volume BSOD Error?

Safe Mode in Windows 8 and Windows 8.1

Safe Mode in Windows 8 and Windows 8.1 is not too different from the Safe Mode found in earlier versions of Windows.

The operating system still loads only the most basic drivers and services, so that it can display a minimal useful interface. The only important difference is that the minimum screen resolution used by Safe Mode has risen from 800x600 pixels to 1024x768 pixels.

1. Use the System Configuration Tool (msconfig.exe) - works in Windows 8 & 8.1

The easiest method for booting into Safe Mode is to use the System Configuration tool, also known as msconfig.exe.

Go to the Boot tab and, in the Boot options section check the box that says "Safe boot". Then, click or tap OK.

You are informed that you need to restart your computer. Click Restart or Exit without restart depending on whether you want to restart now or later.

At the next restart, Windows 8 and Windows 8.1 start in Safe Mode.

2. Use Shift + Restart - works in Windows 8 & 8.1

Another method is to press the Power button at the Windows login screen or in the Settings charm. Then, press and hold the SHIFT key on your keyboard and click Restart.

Windows asks you to choose an option. Press Troubleshoot.

In the Troubleshoot screen, press Advanced options.

In the Advanced options screen, press Startup Settings.

You are informed that you are about to restart in order to change several Windows options, including enabling Safe Mode. Press Restart.

Your computer or device restarts again and displays nine startup settings, including Safe Mode, Safe Mode with Networking and Safe Mode with Command Prompt

Press the F4 key on your keyboard, to enable Safe Mode, F5 to enable Safe Mode with Networking and F6 to enable Safe Mode with Command Prompt. Windows 8 and Windows 8.1 now boot according to the setting you selected.

3. Boot from a System Recovery CD/DVD - works only in Windows 8

In Windows 8, but not in Windows 8.1, you can create a system recovery CD or DVD. Here's the tutorial that shows how it is done: How to Create a System Repair Disc for Windows 7 & Windows 8.

Once you have that disc created, boot from it. When asked to press any key to load its content, do so.

First, you are asked to choose your keyboard layout. Press the layout you want to use. If you want to browse through the available options, press "See more keyboard layouts" until you find the one you want to use.

Then, the Choose an option screen is shown.

From here on, the steps are identical to those shown for method 2.

4. Boot from a System Recovery Memory Stick - works in Windows 8 & 8.1

In Windows 8 and Windows 8.1 you can use the Recovery Media Creator to create a system recovery drive on a USB flash Drive. Details instructions can be found in this tutorial: How to Create a Recovery Drive on a USB Memory Stick in Windows 8 & 8.1".

Boot from the USB memory stick and follow the same instructions as in method 3.

5. Use F8 or Shift + F8 (doesn't work when using UEFI BIOS & SSDs)

In Windows 7, you were able to press F8 just before Windows got loaded, to open the Advanced Boot Options window, where you could choose to start Windows 7 in Safe Mode.

Some websites advise you to press Shift+F8, just before Windows 8 or 8.1 starts loading so that you make it start the recovery mode, from where you can boot into Safe Mode. The problem is that, most times, Shift+F8 and F8 don't work, even though they are correct commands, supported by Windows 8 and Windows 8.1.

This official blog post from Microsoft (Designing for PCs that boot faster than ever before) explains that this behavior is caused by their work in designing a very fast boot procedure. Both Windows 8 and Windows 8.1 have the fastest boot times ever. To quote Steve Sinofsky:

"Windows 8 has a problem – it really can boot up too quickly. So quickly, in fact, that there is no longer time for anything to interrupt boot. When you turn on a Windows 8 PC, there's no longer long enough to detect keystrokes like F2 or F8, much less time to read a message such as "Press F2 for Setup." For the first time in decades, you will no longer be able to interrupt boot and tell your PC to do anything different than what it was already expecting to do."

If you have modern PC with a UEFI BIOS and a fast SSD drive, there's no way you can interrupt the boot procedure with your keypresses. On older PCs, with a classic BIOS and no SSD drive, pressing these keys might still work though.