How to Fix the MBR on a Dual Boot

MBR, or Master Boot Record, is a sector on your hard disk that tells the BIOS (Basic Input/Output System) where the operating system is located. If the Master Boot Record gets corrupted, you will not be able to run any operating system on a dual-boot system. If you have Windows 7 and Windows Vista set up in a dual-boot configuration, you can use either a Windows 7/Windows Vista installation DVD or Windows 7/Windows Vista recovery disc to repair the Master Boot Record.

Things You'll Need

• Windows 7/Windows Vista installation DVD or Windows 7/Windows Vista recovery disc

Instructions

1. Insert a Windows 7/Windows Vista installation DVD or recovery disc and press any key when prompted.

2. Select "Repair your Computer" and select either Windows 7 or Windows Vista as the operating system that you would like to repair.

3. Select the "Command Prompt" option on the "System Recovery Options" dialog box.

4. Type "/fixmbr" and press "Enter" to repair the Master Boot Record on your computer.

5. Eject the Windows 7/Windows Vista installation DVD or recovery disc and restart your computer. Select either Windows Vista or Windows 7 when prompted to boot your computer normally.

References

• Windows: What are the System Recovery Options in Windows 7?
• Microsoft Support: How to Use the Bootrec.exe Tool in the Windows Recovery Environment to Troubleshoot and Repair Startup Issues in Windows
• PC Guide: Master Boot Record (MBR)