Note: If you wish to try the Startup Repair option
first, it is often successful in automatically fixing many different
start up issues, but in this article we will be using the Command Prompt
Error loading operating system
Missing operating system
Invalid partition table
In
Windows 7 and Vista, the procedure to fix the master boot record is a
bit different compared to XP. You have to start up Vista in the Recovery Environment and then run the bootrec command. Here’s how.
1. First, load up the Windows Vista disc in your drive and press any key to boot from the disc.
2. Choose the language, time, currency, etc and click Next.
3. Now click on Repair Your Computer.
4. Choose the operating system to repair and click Next.
Note: You have no OS to select? Solution
select install instead of repair and it will detect your drive, select
cancel and go back to the repair section, your OS will show up now.
5. When the System Recovery Options dialog comes up, choose the Command Prompt.
6. Type the following into the "Command Prompt Window":
bootrec.exe /fixmbr
This
will rebuild the boot configuration data and hopefully fix your
problem. You can also run the command with switches to fix just the
master boot record (/fixmbr), the boot sector (/fixboot), or rebuild the
entire BCD (/rebuildbcd).
(for example)
bootrec.exe /fixmbr
bootrec.exe /fixboot
bootrec.exe /rebuildbcd
Fixing the Master Boot Record (MBR) in Windows 7
1. Turn your computer on, booting from either your Windows 7 Installation DVD or Windows 7 System Recovery Disc. Note: You may need to change the boot order inside your BIOS to have the your DVD drive boot first.
2. After the installation or recovery disc loads, if prompted, select your language settings and then continue. If you are using the installation DVD, when prompted by the following screen select Repair your computer.
3.
The computer will take a moment now to scan itself for any Windows
installations, after which you will likely be given a choice to select
which installation you wish to repair. Select the appropriate Windows
installation from the list and then continue. If by chance a problem is
detected in one of your Windows installations at this initial stage, the
system may also ask you if it can try to repair the problem
automatically. It is up to you if you wish to let the system try to
repair itself, but otherwise just select No.
Note: You have no OS to select? Solution
select install instead of repair and it will detect your drive, select
cancel and go back to the repair section, your OS will show up now.
4. Once you have reached the System Recovery Options
screen, as shown below, you will be faced with a list of choices that
can aid you in repairing a damaged Windows 7 operating system. If you
wish to try the Startup Repair option first, it is often
successful in automatically fixing many different start up issues, but
in this article we will be using the Command Prompt option to resolve our problems manually. So, click Command Prompt to continue.
Step five: Now sitting at the command prompt, enter the following command and then press enter:
bootrec.exe /FixMbr
If successful, you should be greeted with the message The operation completed successfully. That’s it! Your Master Boot Record has been repaired.
While
the above command does fix the MBR, and sometimes that is enough, there
still might be an error with the system partition’s boot sector and
Boot Configuration Data (BCD). This might occur if you have tried to
install another operating system alongside Windows 7, such as Windows
XP. To write a new boot sector, try the following command:
bootrec.exe /FixBoot
If
you are still faced with your Windows 7 installation not being detected
during start up, or if you wish to include more than one operating
system choice to your system’s boot list, you can try the following
command to rebuild your BCD:
bootrec.exe /RebuildBcd
The
above command will scan all your disks for other operating systems
compatible with Windows 7 and allow you to add them to your system’s
boot list. If this fails, you may need to backup the old BCD folder* and
create a new one in its place with the following commands:
bcdedit /export C:\BCD_Backup
c:
cd boot
attrib bcd -s -h -r
ren c:\boot\bcd bcd.old
bootrec /RebuildBcd
*Some
users also find simply deleting the boot folder and retrying the above
steps effective at resolving boot issues, but it is not recommended.