While trying to boot into your Windows 7 OS, if you encounter the message “BOOTMGR is missing”, there may be several reasons for it. But if it’s a software problem you can easily rectify it. You need a Windows 7 installation DVD and type a few commands.
The major problem lies in the Windows 7 boot loader and you need to repair the MBR (Master Boot Record). This is the most common problem and solution. Other problems exist, and require different solutions.
First of all let’s see the many reasons why you get this message immediately after starting the computer.
- Corrupt and Misconfigured files
- Hard-drive and Operating system upgrade issues
- Corrupt Hard-drive sectors (hardware related)
- OutDated BIOS
- Damaged or Loose Hard-Drive Interface cables
[Source : pcsupport.about.com]
Another reason why you get this problematic error message is the computer trying to boot from a non-bootable source. What does this mean? For example if you are trying to boot from an USB or optical drive or floppy drive which is not properly configured to boot from or doesn’t have the facility with that particular BIOS or computer, you can see this message.
The most general case is you have broken something and this error popped up. The other major cause for this problem is when you have installed an older version of Windows like XP on the same PC, that has already Windows 7 installed. This wipes out the boot loader and you need to re-install it.
Boot from the Windows 7 Installation DVD
- Change your BIOS settings to boot from CD/DVD and boot off the install disc. Click through until you see “Repair your computer” link in the lower left hand corner.
- Select the correct installation of Windows (if you’re multiple booting Windows or have more than 1 Windows installed) and click the Next button.
- There you’ll get the System Recovery Options, where you find the option of going to “Command Prompt”.
Repairing the Master Boot Record
- To restore the master boot record, you can simply type in the following command.
- To write a new boot sector onto the system partition use this command. (more helpful)
- To see the remaining options for the base command, you need to type
Replacing Windows XP Boot loader with Windows 7
If you installed Windows 7 first and installed XP next, you’ll find that you can’t boot into Windows 7 anymore. You can use the following commands to restore the Windows 7 boot loader.
bootrec /FixMbr bootrec /FixBoot bootrec /RebuildBcd
Then re-boot. This will replace the XP boot loader and you can boot into Windows 7 again. This will also remove the dreaded “BOOTMGR is missing” message.