Changing the current Disk Drive To change the current disk drive from drive A to drive B, for instance, simply type the alternative drive letter and a colon at the command prompt. After you have entered the command to change drives the prompt should display the letter of the now active drive. Working with Files Files organize information that your computer uses. DOS itself is stored in files that are read into memory when you start your system. Every file has a name.
Most files also have an extension.
In this guide, the file's name and extension are referred to as the filename. Each file must have a name for identification purposes. The name you choose for any file can have no more than eight characters. It must contain only the letters A through Z , the numbers 0 through 9 and cannot contain commas, spaces, backslashes or periods. The copy command is your main tool for organizing and making copies of files.