Ich habe das mal aus der Win XP-Hilfe herauskopiert:
To create an MS-DOS startup disk
The MS-DOS startup disk you create will allow you to boot into MS-DOS.
Insert a floppy disk into your computer's floppy drive.
Open My Computer, and then click the floppy disk drive to select it.
On the File menu, point to the name of the floppy drive, and then click Format.
Under Format options, click Create an MS-DOS startup disk.
Click Start.
Important
Creating an MS-DOS startup disk erases all information on the floppy disk.
Notes
To open My Computer, click Start, and then click My Computer.
The MS-DOS startup disk only allows the system to boot into an MS-DOS prompt. The disk contains no additional tools.
Denke, das reicht.