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Hard Drives & SSDs: Newly Installed Drive Not Available

Created on: May 11, 2013
Last updated: March 3, 2023

Before you can install Mac OS X onto your newly installed drive (or Migrate data to it), make sure the drive is partitioned and formatted properly. Open the Disk Utility and follow these steps:

1. Select the disk in the sidebar at left then click the Partition tab.

2. Next click the "Partition Layout" menu, then choose the number of partitions. One (1) partition is most common for system drives. You won't need to choose a size if there is only one partition. If your create two or more partitions, choose a size for each one or drag the divider between the partitions to resize each relative to the other.

3. Choose a name for your new partition(s).

4. Click the Format pop-up menu to assign a format for each partition you create. We recommend using Mac OS Extended (Journaled).

5. Click Options, then choose GUID Partition Table. 

6. Click Apply.

After you partition the disk, a new icon for each partition appears in Disk Utility. Once you have finished formatting, quit the Disk Utility and continue with the OS X installation – the drive should now be visible within the Installer setup screen. If you need more information on our recommended Migration process, please use the link below.