Computers And Industry

Fixing The Windows 10 Master Boot Record With Bootrec


Bootrec.exe is a Windows utility that reconstructs the Master Boot Record. If the computer suddenly won't boot because a virus or some other type of hard disk corruption, usage of the Bootrec.exe utility may be able to fix the issue.

Each time a computer starts, it looks for the boot sector on a hard drive and when found, loads and runs the programmatic instructions contained therein. These programmatic instructions further instruct the computer to load an advanced operating system like Windows.

However, if the boot sector is corrupted (due to virus or hardware malfunction), the computer will not start and often displays a message indicating no boot device found. If this is the case, the boot sector and often the master boot record need to be reconstructed. And of course, to do this, the Bootrec.exe utility is used.

To fix your master boot record and boot sector, please do the following.

1. Start the computer using the System Recovery USB. At the blue screen that asks you to select your keyboard, select US (or whatever language you require). (2) On the Choose an Option screen, select TroubleShoot. (3) On The Troubleshoot screen, select Advanced Options. (4) On the Advanced Options screen, select Command Prompt. You will now have a command window in which system utilities can be run. (You will see a command prompt something like X:>).
2. In the command window, enter in bootrec /fixMbr and then press Enter.

If the command is successful, a message stating The Operation Completed Successfully will display. If the command was unsuccessful, then stop here. There are physical problems with the hard drive.

3. If the previous step was successful, enter in the command bootrec /fixBoot and then press Enter.

If the command is successful, a message stating The Operation Completed Successfully will display. If the command was unsuccessful, then stop here. There are physical problems with the hard drive.

4. If the previous step was successful, remove the USB recovery drive from the PC and restart the computer.

If the computer restarts, then good. Progress is being made. Note though that there are still more tasks to be done to get a fully functioning system; i.e. tasks such as chkdsk, sfc, and system restore. But all in all, this is a good start.


If The Computer Still Will Not Boot

If the computer still will not boot after fixing the master boot record and the boot sector, then the Boot Configuration Store must be rebuilt. To rebuild the Boot Configuration Store, please do the following.

1. Boot the computer using Windows Recovery USB Drive
2. Enter in the command bootrec /scanOS and then press Enter. This will identify if there are any Windows Installations not configured in the Boot Configuration Store.
3. If there are Windows Installations found that are not in the Boot Configuration Store, Enter in the command bootrec /RebuildBCD and then press Enter. This will add the Windows Installations that are not configured in the Boot Configuration Store.
4. Reboot the system. If you get to the windows logo displaying, the boot sector should be considered good. Again though, there are many other things that must be done to get the PC back to full strength. THings like chkdsk, sfc, and System Restore to name a few.

Note 1. The Bootrec.exe utility is only available When booting from a Windows Recovery Drive. It is not installed as part of the Windows Operating System.

Note 2. If none of this works, I might suggest it is time to do a reinstall of windows. You can save your files by installing into the same partition. However, everything will need to be reinstalled.

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