When you get a Mac, its internal hard drive will have a default name, such as "Macintosh HD." You may add extra internal hard drives, if your Mac can accommodate them, or connect an external hard drive. Each of these drives will appear on the desktop. You might want to rename them to reflect your personality, or identify them according to how you use them. You can easily change hard drive names on your Mac.
Move the mouse to the icon of a hard drive that you want to change the name of.
Click on the hard drive's name to select it. You can also click on the icon of the hard drive, then press the "Return" key on your keyboard to select it.
Type a new name. For example, you might name the start-up drive after yourself, and name one of the external hard drives "Backups 2011." You can type in numbers and symbols for the new name, but you cannot use a colon (":") or start the name of the hard drive with a period ("."). If you try to use a symbol that is incompatible with Mac OS X, you will see a message telling you that the name cannot be used.