format a mac external hard disk in windows

This will cause each available data block to be accessed and written to, and if one is bad then the disk will allocate a spare block in its place and ensure that the logically writable storage space is available for use. To do this, select the volume, then click Secure Erase in the Erase tab, and drag the Secure Erase slider to the second position before clicking OK. Generally a format of the drive in this manner is all that is needed however, some people may wish to test drives further to make sure the media does not contain any bad blocks or other errors beyond the scope of the drive's formatting.įor most in-depth testing of drives, a third-party tool like Drive Genius or Tech Tool Pro can be used, but Disk Utility does support one option, which is to use the Secure Erase option to write zeros to the disk surface. When this is done, the disk should unmount and then remount with the new formatting settings, and now be ready for use. Click the Options button and ensure 'GUID' is selected as the partition scheme.When you select a new partition layout from the drop-down menu, each new partition will be formatted to Mac OS Extended (Journaled) by default, but be sure to double-check this by selecting each in the partition diagram and then choosing the format for it. Select '1 Partition' from the drop-down menu (or more, if you have specific need for more than one volume).Choose the 'Partition' tab that appears.Select the drive device in the list of devices, which is the item above any storage volumes on the drive, and which may show the manufacturer name, media size, and so on.

Format a mac external hard disk in windows