Unmountable Boot Volume: When booting up to your Windows 10/8/7, you may get an error message: “Unmountable Boot Volume”, which usually keeps you from getting into Windows. Well, in this article, we’ll explain everything you need to know about this.
What is the “Unmountable boot volume” error?
The “Unmountable boot volume” problem shows on the Blue Screen of Death, also known as BSOD. These types of errors are known to be unexpected and devastating, as they’re hard to troubleshoot and can happen virtually any time. There’s nothing to worry about, as long as you’ve saved your progress before the crash. Make sure to always save frequently!
Although the new version of the blue screen found in Windows 10 has a friendlier appearance, it still causes just as many issues. The sad emoticon at the top of the screen has become some sort of an internet gag, however, it doesn’t take away from the seriousness of seeing a BSoD.
Losing your files in a computer crash is one thing, but outright not being able to access your system is even worse. This is what the “Unmountable boot volume” error does — as soon as Windows 10 boots up, you’re greeted with an early Blue Screen of Death.
Causes of “Unmountable boot volume” error?
Many of Windows 10’s issues have multiple possible sources, and this one is not an exception. Because of this, we need to take a look at all of the possible causes known at the time of writing.
Thanks to the active and supportive user base of Windows 10, we were able to compile a list of common causes for the “Unmountable boot volume” error.
Corrupted system files. When any of the files responsible for making your system work gets corrupted, it can lead to a number of issues. One of these is being unable to boot into Windows 10, resulting in the “Unmountable boot volume” error. This corruption may be caused by malware, manual error, or an application.
Damage to your hard drive or RAM. Your hard drive and RAM memory are essential parts of your computer. They store your data, both permanent and temporary, and take care of many functions inside your system. If they get damaged, it’s very possible that you won’t be able to boot your computer.
The BIOS is poorly configured. Some computer experts like to tinker with the BIOS function in Windows 10. However, this might go wrong if you don’t know what you’re doing.
A major Windows 10 update rolled out. Some users report that allowing a bigger Windows 10 update to install on their system causes the “Unmountable boot volume” error.
How to Fix An Unmountable Boot Volume in Windows 10
Method 1. Restart your computer
When you received the blue screen unmountable boot volume error at the first, don’t be so worried. Sometimes Windows runs into a temporary hiccup and you never have an issue with it again. Thus, if you see the error while working, restart your computer and try to log in again.
The computer may be able to recover from the error by itself. However, if it won’t let you load Windows at all, you need to consider with more in-depth troubleshooting.
Method 2. Use Windows Automatic Repair to fix unmountable boot volume error
Since your Windows cannot boot normally, you need to use a Windows installation disc or a bootable USB drive to help you access Windows’ troubleshooting tools.
1. Insert the Windows installation disc and start your computer by pressing on the Power button.
2. As soon as the computer starts to boot, press a special key to help you enter the BIOS screen of your computer.
*The Function Key to enter BIOS varies from computer to computer. It may be F8, F9, F12, Esc, and Del keys. Check with the manufacturer of your computer in case the keys are not indicated).
3. When you get into BIOS, select boot from the Windows installation disc.
4. Your computer will boot from the Windows installation disc and you will see the following image, and click Repair your computer at the lower-left corner of your screen.
5. Next, you can do as the following steps:
Click on Troubleshoot -> Advanced options -> Startup Repair.
6. On the next screen, click on Windows 10 (the operating system that is currently installed on your PC).
7. Finally, wait patiently as the utility attempts to repair the files. It can take a long time for the repair process to be over. So, wait patiently and do not try to end or abort the process.
After that, the issue may be solved and you can exit the installer and try to boot the PC normally. If the Windows Startup Repair didn’t solve your problem, move on.
Method 3. Repair Master Boot Record
We have learned before that the corrupted system files may cause the unmountable boot volume in Windows 10. The Master Boot Record (MBR) contains information where lives on 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. Thus, you can fix the error by repairing the MBR.
1. Boot from the Windows 10 installation media again, and do as the following steps:
2. At the Command Prompt, type bootrec /fixmbr and press Enter key, it will run an MBR repair immediately.
3. After done, run the following commands one at a time to attempt additional repairs:
4. Type exit to leave the Command Prompt once these complete. Then reboot again and see if the error continues to pop up.
Method 4. Run CHKDSK command
If Windows Startup Repair and MBR repair didn’t solve your problem, you need to check whether there is hard drive error or not with CHKDSK command since the hard drive error may also cause the unmountable boot volume in Windows 10.
Use the same way in Method 3 to open the Commend Prompt, then, enter the command chkdsk /r c:
The /r flag locates any bad sectors on your disk and fixes those errors. If you don’t include this, Chkdsk will simply report errors it finds.
In case your usual boot drive is not “C” you will need to replace “C:” with a bootabel drive letter that is applicable to your computer.
This would take a long time and you need to give your computer all the time that it requires to fix the errors on the hard drive.
After the CHKDSK is complete finished, restart your computer and see if the unmountable boot volume error has been resolved.
Method 5. Try an SFC Scan
System File Checker (SFC) is another important utility that can look for corrupted Windows system files and attempts to fix them. If the methods above have not fixed your issue, you can try to use SFC Scan to solve the problem.
Open Command Prompt with Windows installation disc again, enter the command sfc /scannow and press Enter key.
Wait until the process completes. It will tell you if it fixed anything. After that, reboot and try to load into Windows.
Method 6. Fix unmountable boot volume error without Windows installation disc
No matter doing MBR repair or checking hard drive errors, it all needs a Windows installation disc. But what if you do not have a Windows installation disc?
If you do not have a Windows installation disc, you can make use of third-party software to help you fix unmountable boot volume error in Windows 10/8/7. AOMEI Partition Assistant Standard is a really powerful and free software that can not only help you create bootable media (USB drive, CD/DVD) but also repair MBR, check hard drive error.
Step 1. Free download AOMEI Partition Assistant to another valuable Windows computer. And use it to create bootable media.
Step 2. Insert the bootable media you create before to the unbootable computer, enter the BIOS and change the boot order so that you can boot from the bootable USB.
Step 3. You will get into the main interface of AOMEI Partition Assistant. To repair MBR, here you need to right click the hard you need to repair, and select Rebuild MBR.
Step 4. Choose the operating system you are using currently. Click OK.
Step 5. Finally, click Apply at the toolbar to execute the progress.
Wait till the progress done, remove the bootable media and reboot your computer to see if the problem is solved.
If not, you can continue to check and fix corrupted system file with this freeware, you can right click the system partition, and select “Check Partition” on the pop-up menu to do the task.
Method 7. Test hard drive with AOMEI Partition Assistant Standard
If none of the methods we mentioned above solved your problem, you may have a hardware issue: your hard drive could be corrupted, dying, or have a faulty connection. If there is no problem with the connection, you can get into AOMEI Partition Assistant again, and do a Surface Test to check the bad sectors on your hard drive.
Step 1. Use the bootable media you created by AOMEI Partition Assistant Standard. Right-click the disk that needs to test, select Surface Test.
Step 2. Click Quick Check, and click Start. If there is a bad sector on the hard drive, it will be marked as red, if not, it is green.
Note: You can enjoy more functions, such as recovering lost boot volume, clone NVMe to NVMe SSD, etc., you can upgrade it to the Professional version.
If you got a hard drive problem, you need to fix it, or you can replace it with a new hard drive. But if there is no problem with your hard drive, the only thing you can do is to reinstall Windows.
The Worse is that nothing can help you fix unmountable boot volume in Windows 10/8/7 but only reinstall Windows. With this operation, you can get your computer back to work again but lose all the data and files on your computer (unless you have backed up the system before, which allows you to restore the computer to an earlier date).
1. Shut down the computer by pressing the Power button.
2. Using Windows installation disc to get into Windows.
3. Click Install now when it shows on the screen.
4. Follow the onscreen prompts to reinstall Windows 10, or Windows 7, Windows 8 on your computer.