Hard drives in Seagate's FreeAgent line -- except for the Go Pro for Mac and the Go for Mac -- ship with NTFS, a file system designed for Windows. Your MacBook can not read or write to a NTFS drive, so you will need to reformat it to a Mac-compatible file system. Formatting a drive will erase all its contents, so back up the drive first if you've already copied files to it on another computer.
Connect the FreeAgent to any open USB port on your MacBook.
Open the Apple menu and click "Go" and then "Utilities." Double-click "Disk Utility."
Select the FreeAgent drive and open the Partition tab. Open the "Volume Scheme" drop-down menu and change the setting from "Current" to "1 Partition."
Click "Options," select "GUID Partition Table" and press "OK."
Change the "Format" setting to "Mac OS Extended." Optionally, type a name for your disk in the "Name" text box.
Click "Apply" and then "Partition" to confirm that you want to erase the drive and reformat it. If Time Machine appears after the format, click "Cancel" unless you want to use the drive for system backups.
Some MacBooks do not provide enough power via USB to run a FreeAgent drive. If the disk doesn't turn on when you plug it in, you can buy either a powered USB hub or a Y splitter cable to connect the drive to two USB ports.
Information in this article applies to Mac OS 10.5 and newer. It may vary with other versions of the operating system.
If you have a FreeAgent GoFlex or Seagate Backup Plus drive, you don't need to reformat the disk before copying files to it -- these drives work on both Windows and Mac, as long as you install the included software.
If the process fails on Mac OS 10.5 or 10.6, dismount all DMG files before starting. If it still doesn't work, try using the version of Disk Utility on your system install disc instead. Insert the disc, reboot while holding "Option" and pick "OS X Install Disk."
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