How to Reinstall MBR
- 1). Insert the installation DVD into the drive and reboot. The Windows installation DVD is bootable, so press "Enter" when prompted to boot to the DVD.
- 2). Choose your language, time zone and keyboard settings. Click "Next." Click the link labeled "Repair Your Computer" in the next window.
- 3). Click the operating system you want to repair. For most people, only one operating system is installed, so click the operating system in the list and click "Next."
- 4). Click "Command Prompt" in the Recover Console window. This opens your Recover Console command prompt.
- 5). Type the following commands into the prompt to repair your MBR files:
<br /><br /><br /><br />bootsect /nt60 C:bootsect /nt60 sys<br /><br />bootsect /nt60 all<br /><br /><br /><br />
These commands repair your MBR, so you can fix boot issues with your Windows computer.
Source...