Simple erase in Mac OS
IMPORTANT NOTE: Following the procedure below will ERASE ALL DATA on the drive. Prior to following these directions, verify important data is stored securely on a different storage device.
Begin by opening the Disk Utility program. This is found in Applications, then Utilities.
When the program opens, click the drive needing to be formatted on the left side of the window. In this example, we are erasing a 20GB drive (listed as 18.6 GB.)
Click the Erase tab along the top.
Change the options to be appropriate for the drive's use. Ordinarily, a Volume Format of Mac OS Extended (Journaled) is best. If there are special circumstances, choose the format appropriate for the situation.
The Name field will set the name the drive is identified by. This will appear by the icon on the desktop used to access the drive.
Click Erase when the settings are correct.
Finally, there is a warning and a summary of what is about to happen. Choose Erase to complete the process. It will take fewer than 30 seconds on most computers.
What is the situation you are facing?