If you want to start up your Toshiba Satellite laptop computer into an MS-DOS style command prompt instead of the Windows operating system, you will need to do so using your machine's "Advanced Boot Options" settings page. This is the page that allows you to perform a variety of functions in addition to booting into a DOS prompt, including starting in "Safe Mode" and other options that can allow you to repair problems with your machine.
Restart your Toshiba Satellite laptop computer.
Press "F8" to enter your Toshiba's "Advanced Boot Options" menu.
Highlight the "Safe mode with command prompt" option.
Hit "Enter" to start up your Toshiba Satellite laptop computer in safe mode with a DOS command prompt.