How to fix MBR (Master Boot Record ) damages and issues -HDD

How to fix MBR (Master Boot Record ) damages and issues - Fdisk commands

MBR (Master Boot Record ) is the first sector(512-byte) in your hard disk where the the primary partition table and instructions for BIOS to boot the computer are stored. Any corruption to MBR is fatal as it can even stop our computer from booting. This MBR damage can occur in different ways:

1. Possible Virus attack

2. Hard disk errors

3. Multiple OS installation


Possible Reasons of MBR Damage

There are some kind of viruses called MBR viruse can damage the Master Boot Record of your computer by replacing the original MBR with new one created by them. Original MBR sector will be moved to some other locations in the hard disk. These MBR viruses can start when the system boot-ups (ie: Even before Operating System loaded). Other possible reasons are hard disk errors and improper installation of multiple operating systems.

The effects of corrupted MBR is difficulty in starting computer , cannot boot computer in safe mode and other available safe mode options etc. The worst cause is not booting computer.

To fix MBR we have some tools which operates in recovery mode. We cannot
actually change the MBR while Windows is running.

commands to Fix MBR issues

Fdisk /mbr

The MS-DOS command Fdisk /mbr rewrites the MBR on the hard disk, to resolve MBR
corruptions. This command is useless if your computer is infected with MBR viruses ,they will again reinfect the new MBR sector and the issue persists. Hardware specialists are not recommending this command to fix MBR issues and they recommend the second Fdisk command - Fixmbr.


Fixmbr - command to fix MBR in Recovery Console


It is another DOS command to fix MBR corruptions. It also work as the Fdisk /mbr command.The fixmbr command is only available from within the Recovery Console in Windows 2000 and above. In fixmrb command we can specify the location of master boot record if we are not going to fix the mbr of master boot device. The the command look like:

fixmbr (device_name)


You need to boot your computer using Windows disk in order to use fixmbr command.

Steps to run Fixmbr on your computer

1. Restart computer

Restart your computer with Windows CD where DVD/CD drive is the primary boot device.


2. Recovery console

Press the R key to start the Recovery Console when it prompts.

3. In Recovery Console command prompt, type fixmbr and follow the instructions



Note: It is dangerous to play with MBR without proper knowledge about it. Any mistakes can make your computer non-bootable.