A disk partition is used to configure your hard disk with a file system, which helps your computer recognise and properly manage it. An MS-DOS boot partition is achieved by creating a primary partition. Your primary partition must be active to successfully boot an operating system. This procedure is performed through a boot disk set-up utility from the MS-DOS command prompt.
Turn on your computer and press "F8" to launch the Windows Advanced Options menu. Select "Safe Mode With Command Prompt" and press "Enter." Alternatively, you may also click "Start," go to "Run," type "Cmd" and press "OK" from your Windows operating system.
Insert your boot disk into the computer's floppy disk drive. Type your floppy disk's drive letter, followed by a colon and press "Enter." The drive in question is typically "A" by default, so an example of this would be "A:".
Type "Fdisk" and press "Enter" to launch the MS-DOS proprietary partition utility. Type "Y" when asked "Do You Wish To Enable Large Disk Support?" and press "Enter." Note that your hard disk's capacity must be larger than 512MB. Otherwise, type "N" and press "Enter" so your hard disk is configured with an appropriate file system.
Type the number "5" to select which disk you wish to create the boot partition. Select from the list of available hard disks by typing their respective number and pressing "Enter."
Type the number "1" to select "Create Primary DOS Partition" and press "Enter." Type "Y" to have the system partition as the entire hard disk's capacity and set it to "Active." As a result, an active primary partition allows your hard disk to become bootable.
Note that a boot disk is necessary to launch the MS-DOS Fdisk utility. See resources for available download locations.