For fixing or repairing the Master Boot Record, follow the steps given below:
- Firstly, boot your system from a Windows 10 installation media.
- Now navigate to the following path: Repair your computer -> Troubleshoot -> Advanced Options -> Command Prompt.
- On the Command Prompt window type “bootrec /fixmbr” and then press Enter. This command will immediately run an MBR repairing process.
- Once done, now run the following commands individually. Make sure you press Enter after each of the commands:
bootrec /fixboot
bootrec /rebuildbcd
- After the process is fully completed, type Exit to leave the Command Prompt
- Once you are entirely done, boot your system manually, and check whether the issue is resolved now or if it persists.
FIX 3: Run CHKDSK (Check Disk) command:
As said above, a corrupted hard disk may trigger the “UNMOUNTABLE_BOOT_VOLUME” error, leading you to BSOD. To make sure if this is the case with you, and get rid of it successfully, follow the steps given below:
- Firstly, boot your system from a Windows 10 DVD.
- Now navigate to the following path: Repair your computer -> Troubleshoot -> Advanced Options -> Command Prompt.
- On the Command Prompt window, type or Copy + Paste the following command and then press Enter.
chkdsk /r c: 
- It will start an automated process that might take a longer duration. Make sure you do not abort it in between.
- Once done, try to boot your system normally and check whether to enter Windows or not.
IMPORTANT INFORMATION:
- “/r” flag generally locates bad sectors on your disk and then automatically fix those errors. Without including the “/r” flag, the command will report errors it finds.
- If your boot drive is not “C” then replace “C:” with a bootable drive letter which is ideal for your PC.
FIX 4: Run System File Checker (SFC) scan:
As per some of the suffered users, the “UNMOUNTABLE_BOOT_VOLUME” error might also get triggered due to corrupt system files. To mark out this possibility and resolve the error, run the SFC scan on the Command prompt window. For doing so, follow the steps given below:
- Firstly, boot your system from a Windows 10 DVD.
- Now navigate to the following path: Repair your computer -> Troubleshoot -> Advanced Options -> Command Prompt.
- Now in the Command Prompt window, type or Copy + Paste the following command and then press Enter.
sfc /scannow
- Let the command run a scan. It will notify you if it finds any error and would repair it automatically. If the same happens, let it process. Once done, go and boot your system again and check whether you are now able to enter the Windows screen or not.
If it does not find any error, then it states that there’s no corrupt system file on your computer.
These were some of the most effective and easy methods that would help you get along with the “UNMOUNTABLE_BOOT_VOLUME” error. All of the fixes listed above are tired, tested, and have worked for numerous suffered users.
However, if none of them works for you, we recommend you to try some basic workarounds. Firstly, reboot your system and check whether it helps. You can also try to reinstall Windows 10 and check whether it helps or not. ( make sure you have made a file backup before). After reading this article, if you have any queries or feedback, please write down the comment in the below comment box.
