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To erase your computer’s startup disk, you must start up from another disk, such as an OS X installation disc or from the Recovery Disk.
#REFORMAT DISK FOR MAC FULL#
If you don’t want data recovered from a solid-state drive, use full disk encryption. You can’t securely erase a CD, DVD, or a solid-state drive. Securely erasing a partition erases all the files on that partition but does not affect other partitions. Securely erasing a disk erases files on all its partitions. Writing over the files several times is more secure than writing over them once, but it takes longer. You can choose how many times to write over the files. When securely erasing a disk or partition, Disk Utility writes over the erased files, so they can never be recovered. Many commonly available disk recovery apps can easily recover the files. When erasing a disk or partition, Disk Utility does not erase the actual files it erases only the information used to access the files. You can securely erase a disk or partition to make sure the confidential information it contains cannot be recovered. The following is a summary of the Disk Utility help available from the Help menu when running the Disk Utility application: Securely erase a disk in OS X 10.8 or newer A Recovery Disk can also be created on an external hard disk or thumb drive using the Recovery Disk Assistant: All new OS devices come with a built-in Recovery Disk which can be used by restarting and holding down the R key. Disk Utility has shipped on all OS X versions in /Applications/Utilities folder. Secure Erase is documented in the Help menu of the Disk Utility application.
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Instead, choose Installer > Open Disk Utilities.

#REFORMAT DISK FOR MAC MAC OS X#
These steps assume you have a Mac OS X 10.2.3 or later CD: Note:This refers to a full Mac OS X 10.2.3 or later CD included with a computer, not to the update-only 10.2.3 CD. To erase a Macintosh hard disk you can boot with a different disk and use the Disk Utility.
