If you are running Microsoft Windows and has a corrupted Master Boot Records or MBR, you can use Windows own utility to fix the problem. These methods are only useful in a single-boot environment as what it does is nothing more than to clear your Master Boot Records and create a single entry which is your currently running Windows operating system. You'll need to find a dedicated MBR recovery software if you require anything more than this.
If you're running older Windows operating system such Windows XP, you can use
fdisk to get the job done. Fdisk has an undocumented feature which allows you to write the MBR with the following command.
In Vista and newer Windows operating system such as Windows 7, the fdisk option is no longer available, bootrec you can use the program
bootrec which does the same thing.
You can access the program from the installer DVD if your system is totally unbootable by going to the command prompt after booting from the DVD by selecting the menu “Repair your computer” and run the following command;