Creating a bootable MS-DOS start-up disk allows you to access your computer and its files externally. This can be especially helpful if you are experiencing severe virus and system issues within Windows. Creating a USB start-up disk requires that you format your external USB drive to be used as a boot-up disk. The formatting process deletes all files and data associated with your USB drive. Use a blank USB drive, or back up the files on your USB flash drive before beginning the formatting process.
Insert a USB drive into an available USB port on your computer. Turn on your computer.
Click on the "Start" menu icon located on the bottom left-hand corner of your screen. Click on "All Programs," and select the "Accessories" drop-down menu. Click on the "Command Prompt" application in the drop-down menu. A black and white MS-DOS prompt window will appear.
Type "DISKPART," and then hit the "Enter" key.
Type "LIST DISK" followed by the Enter key to proceed.
Select your disk number from the list of available disks on your computer by typing the disk number into the MS-DOS prompt window. The disks will be listed as DISK 1, DISK 2, and so on. If your computer only has one hard drive installed, your USB drive will be DISK 2. Type in the appropriate disk number followed by hitting the "Enter" key.
Type the following commands one-by-one followed by the Enter key:
CREATE PARTITION PRIMARY
SELECT PARTITION 1