To run the command, you need to open a command prompt, or terminal. Guessing you're on Windows, in which case you're looking for cmd on any of the latest versions. Forget if it is labelled something else for stuff older than vista (99% sure is was "command prompt" in win95, but I really hope you're not still on that), and I'm not sure what it is for windows 8.
Originally Posted by Lrrpie-CT
I destroy drives for clients all the time. Sometimes, intentionally.