What is MBR? MBR stands for Master Boot Record and is the first sector of your hard drive that basically tells the BIOS where to look for the operating system on your computer.
If, for any reason, the MBR gets damaged or corrupted, the operating system will fail to boot. Typically you see error messages such as:
Error loading operating system Operating system missing Invalid partition table
These messages are definitely not fun, especially if you are not familiar with computers. Most people automatically think their computers are dead! However, it is not. While in the IT department, these errors are actually preferable to other types of Windows errors. Why?
Well, it’s actually pretty easy to fix the Master Boot Record in XP and Vista. All you have to do is load the Recovery Console and execute a simple command. All your data, applications, settings, etc. will remain intact on the disk, and after fixing the MBR, the computer will boot normally.
MBR repair in Windows XP
So how do you repair a damaged MBR? Here are the steps to follow:
1. First, restart your computer with the Windows XP installation disc in your CD-ROM drive. If you don’t have the original disc, borrow it or download the ISO image from a torrent site.
2. When prompted, boot from CD by pressing any key. If Windows boots automatically, you will first need to enter BIOS setup and change the boot device order to start from the CD-ROM drive.
3. After downloading the installation, you will see the option to press R to repair the Windows installation.
4. After the Recovery Console boots, you will need to enter the number corresponding to your Windows installation. This is usually just 1. Press Enter and then enter the administrator password.
5. Now enter fixmbr at the command line. The damaged MBR will now be replaced with a new Master Boot Record and your computer can now boot normally. Note that you can also run the fixboot command to restore the boot sector with a new one.
Also, make sure you only use these commands on a system with one operating system installed. If you have multiple operating systems installed, fixmbr and fixboot can mess things up.
MBR repair in Vista
In Vista, the procedure for fixing the Master Boot Record is slightly different. You must start Vista in a recovery environment and then run the bootrec command. Here’s how.
1. First, load the Windows Vista disc into the drive and press any key to boot from the disc.
2. Select language, time, currency, etc. And click Next. Now click “Repair your computer”.
3. Select the operating system to recover and click Next. When the System Recovery Options dialog box appears, select Command Prompt.
4. Now type bootrec.exe and press Enter. This will restore your boot config data and hopefully fix your problem. You can also run a command with switches to fix only the master boot record (/ fixmbr), the boot sector (/ fixboot), or rebuild the entire BCD (/ rebuildbcd).
If you’re still having problems booting Windows, please leave a comment and I’ll see if I can help! Enjoy!