Master Boot Record (MBR) is used for your computer to find the location of the operating system to allow Windows 10 to boot

1. Create a Windows 10 USB bootable media

2. Change your device BIOS settings to start from the bootable media

3. Start your PC with the bootable media

4. Click the Next button in the Windows 10 Setup.

5. Click the Repair your computer button in the lower-left corner

6. Click the Troubleshoot button

7. Click the Advanced options button

8. Click the Command Prompt button

9. In Command Prompt environment (CMD), enter the following commands:

Bootrec /fixBoot

Bootrec /ScanOS

Bootrec /RebuildBcd

10. If you are trying to troubleshoot a “Bootmgr Is Missing” error and rebuilding the BCD store doesn’t fix the problem, you can use the following commands:

BCDedit /export C:BCD_Backup

C:

CD boot

Attrib BCD -s -h -r

Ren C:ootcd bcd.old

Bootrec /RebuildBcd

Press Y to confirm adding Windows 10 to the list of bootable operating system on your computer.

11. Close Command Prompt and restart the computer