If you want to run MS DOS prompt the do the following on your computer

1. Click Start.
2. Click Run.
3. Type cmd or command and press enter.

If you're attempting to get into a MS-DOS prompt for doing the troubleshoot then boot the computer into Safe Mode.If the user of Windows 2000 and XP are unable to boot their computer into Normal Windows mode or Safe mode can also enter the recovery console for managing their computer from a prompt.

At last, if you are still experiencing the issues of getting into the Windows NT, 2000, or XP it may be compulsory to make run the troubleshooting steps from a MS-DOS prompt. It is suggested that the Network Administrator get into the MS-DOS prompt by using either a standard MS-DOS boot diskette.