If you are working only with MS-DOS without any other operating systems, then your computer should be booted into a MS-DOS prompt automatically unless there is a shell or other program loaded automatically on the screen. If the computer is not getting you to a MS-DOS prompt, then reboot the computer and while the computer is booting, press the from the keyboard till you don’t see the message as "Starting MS-DOS" or the MS-DOS version.

This will load the defaulted standard of MS-DOS. By following the above information if you successfully get into a MS-DOS prompt and you would like to prevent the computer from loading the program that is preventing you from getting in to a MS-DOS prompt, or if you are looking to fix the possible error messages you may be receiving when booting the computer you will get the files on the screen.