Erase an External Hard Drive

To erase an external hard drive, open your Applications folder, and then your Utilities folder, and then run the Disk Utility program. On the left side of the window, click on the hard drive you want to erase. (Careful! Don't choose your computer's hard drive!) Then on the right side, choose the Erase tab. For Format, choose Mac OS X Extended (Journaled). For Name, put the name you want the erased hard drive to have. If you want your erased data to be secure, click the Security Options button and choose either Zero Out Data or 7-Pass Erase. Then click the Erase button.