WARNING:  This will remove some multi-operating system boot . . . → Read More: Fdisk MBR]]> The Fdisk MBR (master boot record) is an undocumented switch that can be activated by typing at the DOS prompt “fdisk /mbr”.  This will rebuild and rewrite the hard disk MBR file.  This can be very handy if the MBR file becomes corrupted or virus infected.

WARNING:  This will remove some multi-operating system boot functions.

At one time I used this feature daily in a lab to remove a virus that we were having difficulty cleaning from all our lab computers.  Today if you install AVG or one of the other top anti-virus programs you should be safe from MBR or boot record viruses.  The only other problem you might encounter is a corrupted MBR file, which can happen when some programs modify the MBR during installation.  To fix the MBR and get your computer to boot properly you would need to boot from either a DOS partition on the hard drive or boot from a DOS bootable floppy, CDROM, or flash drive.  DOS files can be retrieved from either MSDOS, Windows 95, 98, or ME.  You can even format a floppy disk and include the DOS (Windows ME) system startup files by formatting a floppy on a Windows XP computer.  You can also create a DOS bootable floppy by using a CD burning program like Nero to create bootable CDs.  To create a DOS bootable flash drive there are several utilities on the Internet that will format a USB flash drive and allow you to load the DOS startup files.  I use USB bootable flash drives daily to maintain lab computers.  I have also created several YouTube videos that can help you with Fdisk, DOS, and creating bootable flash drives:

Fdisk MBR

The Fdisk MBR website has additional articles on this subject you might find useful.

YouTube Video about DOS:

YouTube video about Fdisk:

YouTube video about creating a bootable flash drive: