Anyone who’s ever played around with partitions and dual booting different OS’ knows that the Master Boot Record (MBR) is always overwritten and keeps the user from booting back into their original Windows 7 installation. Recently, I underwent the tedious task of trying to install Mac OSX Leopard on PC hardware and ran into many issues including a problem with restoring the MBR to the previous Windows 7 installation. Usually, running the repair option from the Windows 7 Install disc works it’s magic and the Startup Repair fixes the issue, but it was not to be the case this time. What I had to do, was use the command prompt and use the BOOTSECT.EXE command to fix the MBR. Why Startup Repair didn’t work, I don’t know…it usually does, but everything was successfully restored and Windows 7 is running fine now.
Just a fair warning: If you are not comfortable with the command prompt, dual boots and partitions, you may not want to attempt this method. While it is safe, I would recommend having someone who is familiar with these procedures perform this restore.
Here’s how to update the bootsector code:
Boot from the Windows 7 DVD or image and follow the prompts until you reach the option to Repair Your Computer.
You will be asked which Windows installation you would like to recover. Check the option for Use Repair Tools that can help fix problems starting Windows. Select the appropriate installation and click Next.
You will then be given the following screen of Repair options. Normally, you can just select Startup Repair and Windows will do its thing and take care of everything automatically. I would always attempt this option first before delving into the command prompt. However, if the Startup Repair does not work on your installation, you can select the Command Prompt and continue.
We will need to access the CD Drive, so type the appropriate drive letter (e.g. E:) at the X:\Sources=> prompt, then hit Enter.
Now, with the E:\ prompt up, we need to switch to the boot prompt, so type CD Boot.
The Prompt should change to E:\boot>. Type bootsect /nt60 SYS (there should be a space between bootsect and the ‘/’) then hit Enter.
You should receive a message that the ‘Bootcode was successfully updated on all targeted volumes’.
Type exit to return to the recovery options window and Restart or Shutdown.
Hope this helps. Happy dual booting.