Friday 7 October 2011

Fix MBR in Window XP, Vista and 7

What is MBRHow to Fix MBR in Window XP, Vista and 7When the computer system is turned ON the first program that it loads is BIOS (Basic Input Output System).The BIOS also need a memory address from where it can load its Boot Program known as MBR(Master Boot Record) or  Master Boot Sector or Boot Sector which starts the further processing .The exact location of this boot record is cylinder 0, head 0 and sector 1 which is the first available space on harddisk. MBR contains all the necessary information for loading the operating system.

Some Error Messages and their Causes:

If your system’s  MBR gets corrupted your operating system will not load and this is commonly referred as Window Crash.MBR can become corrupted due to viruses in your operating system or sudden Power OFF.Following are the error messages you will get due to corrupt MBR
  • Error in loading operating system
  • Missing operating system
  • Invalid partition table
You can also get these error messages when you Multiboot your system i.e. installs two operating systems (like Window 7 & LINUX)  and uninstall any of them. Now when you try to load the other OS it goes the memory location where the boot loader of uninstalled operating system was present and try to load it. As there is no boot loader of that operating system then it will produce one of the above mentioned error messages.
When a user get these error messages then the first thought comes in his mind is that his windows has been corrupted and he has to reinstall a fresh copy of the operating system.
The thing is that the boot program of the installed OS is present at different memory location on the disk  and you have to map the boot loader with the operating system ,not to reinstall the fully OS again.

How to Fix MBR in Windows Operating System

Fix MBR for windows XP:

  • First of all, restart your computer and insert Windows XP setup disk in the CD drive.
  • Once the setup loads, you will see the following options just press R to repair your Windows.
111 How to Fix MBR in Window XP, Vista and 7
  • Once the Recovery Console loads up, press 1 which will corresponds to your Windows installation and hit Enter. Now type your Administrator password.
3 How to Fix MBR in Window XP, Vista and 7
  • Now in the command prompt window type fixmbr and press Enter. Your MBR will now be replaced with a new MBR. You can also run the fixboot command to repair the boot sector.
Note:- Make sure you only use these commands on a system where only one operating system has installed. If you run these commands where more than one operating system has installed then fixmbr and fixboot could mess up everything.

Fix MBR for windows Vista & 7:

  • First, insert Windows Vista or window 7 CD in the disk drive and press any key to boot from the disc.
  • Now Choose the language, time, currency etc and click Next. Now click on Repair Your Computer.
4 How to Fix MBR in Window XP, Vista and 7
  • Select the operating system to repair option and then click Next. Now in the System Recovery Options window choose the Command Prompt.
5 How to Fix MBR in Window XP, Vista and 7
  • For Window VISTA in the command prompt window type bootrec.exe and press Enter.
  • For Window 7 in the command prompt window type bootsect /nt60 C:\ and press Enter where C: is the disk drive where your operating system has installed. You can change this drive letter according to your installed operating system’s location.
  • Once done, eject the disc and restart your computer for the change to take effect.
That’s it now your operating system will boot normally without any problem.