Updated February 10, 2017 Back up the data that is on the hard drive you want to format. Reformatting your hard drive will remove all of the data on the hard drive, so back up anything you want to keep. Click “Start” and click “Run.” This will open the Run dialog box. Type “cmd” in the text field and press “Enter” or click “OK.” This will open the command prompt. Type “format c:” into the command prompt and press “Enter.” The computer will begin to format the hard drive. Only format a hard drive if you have a system restore disc so that you can install the operating system. Writer Bio
