Tuesday, 3 November 2009

Repair MBR for Windows 7 installed on MacBook

A couple of days back, I installed Ubuntu Karmic (Ubuntu 9.10) on my MacBook to give me a triple OS boot option (which I will write about in another post). My MacBook also had Windows 7 Home Premium Edition installed previously. During the installation, I selected Ubuntu to write the Grub onto a separately created partition (formatted to FAT32) under the Advanced Installation option. Following the installation, I found that the Windows 7 MBR (Master Boot Record) was overwritten by GRUB (Grand Unified Boot Loader). As a result I got a message "Missing Operating System" when I started Windows 7. This is how to get it back.

(Caution: This tutorial is only for restoring MBR on Windows 7. Do not use this tutorial if you are unsure for whatever reason).

Step 1: Insert the original Windows 7 DVD. (For Mac users, press the Alt (or Option) Key and hold until you see the DVD symbol and choose it).

Step 2: Choose the suitable Language, Time and Keyboard.

Step 3: Press Next and choose the option Repair your Computer. Do not press Install Now.

Step 4: Select the Windows 7 Installation and press Next.

Step 5: You will be presented with five options; (1) Startup Repair, (2) System Restore, (3) Windows Complete PC Restore, (4) Windows Memory Diagnostic Tool and (5) Command Prompt. Select the fifth option.

Step 6: You will end up at something like this X:\>Sources. Get set to enter some DOS commands.

Step 7: Type the command "cd.." (without quotes). This will take you to the root directory X:\>.

Step 8: Type the command "cd boot" (without quotes). This will take you to the boot directory, which should look like this X:\>boot.

Step 9: Type the final command "bootsect /nt60 C:" (once again without quotes). This would have restored your MBR to its previous state.

Step 10: Eject the DVD and press Ctrl-Alt-Del for PC users. For Mac users do a Hard Reset (by pressing power button and holding it until it shuts down).

Your MBR would have been restored. I did this on a MacBook and it worked.


Alex said...

Thanks, this helped when playing with Lucid Install on new macbook.

arthur said...

please i need help!!! the command prompt cd boot comes back "the system cannot find the path specified" i dont know what to do now. ive gotten so far with your help and have now hit a brick wall

Derrick said...

Yes there is no boot directory. I still typed the command it seemed to get rid of the grub loader but now I just get flashing cursor top left of the screen and nothing else!.

Anonomous said...

Help it is stuck at starting windows

tonwin said...

Your continued help and very useful.

Aofe Lasz said...

I also use windows 7 i did windows 7 starter iso usb free download and i am getting well results