Step 1: Meet Disk Utility
The Disk Utility application can be found in /Applications/Utilities. The left column lists the Macundefineds storage devices. Listed under each drive are the partitions. (Weundefinedll cover how to partition a hard drive in a separate tutorial.) For example, in the screenshot here, the first drive listed (320.07 Hitachi) is the internal drive of my MacBook Pro. Listed underneath that is the one partition thatundefineds on the internal drive called Macintosh. The second drive listed (1.04 GB Generic Flash Disk) is an external flash thumb drive with a single partition called 1GB USB. The last device listed is the internal optical drive. There is a set of tabs across the top right part of Disk Utility. To format a drive (or format a partition), the first step is to select it in the left column and click on the Erase tabundefineddonundefinedt click on the Erase button on the lower part of the interface just yet. Disk Utility canundefinedt format the hard drive thatundefineds being used as the startup disk, which is usually the Macundefineds internal drive. If you want to format the startup disk (which will wipe out all the data, including the system) you need to use a different drive as the startup disk or startup using the Mac OS X installation disc. You can run Disk Utility from the installation disc.