MBR refers to Master Boot Record. It’s the first sector of hard disk that helps the BIOS to find the operating system location on your hard disk. Sometimes MBR may get corrupted. If such a thing happens your computer won’t be able to load Windows. You’ll end up receiving errors like- Error loading operating system, Missing operating system, Invalid partition table, etc.
If you encountered such a problem on Windows 7 then here’s how you fix it:
Firstly, Insert Win 7 installation DVD and boot from DVD drive. You need to set primary booting device to DVD drive. This can be done in BIOS. To boot from disc you’ll need to press any key on your keyboard.
Now, choose your default “Language”, “Time”, and “keyboard Input” on the first window and click next.
On the third step you’ll see three options on the screen. Click on “Repair Your Computer”. This will open the System Recovery window.
Select the “Command Prompt” option. We need to start command prompt in order to run “bootsect.exe” which helps in solving the problem.
Since Bootsect is located inside the boot folder, you need to change the directory to boot. Now, you need to make use of the following commands:
bootsect /nt60 C:\
bootsect /nt60 SYS
bootsect /nt60 ALL
Use the first command if you have installed Windows 7 on “C” drive. If it’s located on any other drive or the first command doesn’t work then try the other two commands. Once, you’re done, simply eject the disc and restart computer. Voila! You should now be able to boot into Windows 7.