How to Recover GUID Partition Table

A GUID Partition Table allows a drive to boot an Intel-based Mac OS X computer. Formatting a drive this way is necessary if you plan to use the drive as a Mac OS X installer or a bootable backup drive. Recovering, reformatting and making the drive bootable are fairly simple using Mac OS X's built-in disk management application, Disk Utility.

Instructions

1. Connect the drive to the computer, if it is not already, via USB or FireWire cable.

2. Open the "Disk Utility" application.

3. Select the drive in the left-hand side of the Disk Utility application. Click the "Partition" tab in the main window.

4. Select the desired partitioning scheme from the "Volume Scheme" drop-down menu. If you do not want multiple partitions, simply select "1 Partition." If you create multiple partitions, select the desired partition by clicking on it, beneath "Volume Scheme" before continuing to the next step.

5. Click "Options." Select "GUID Partition Table," and click "OK."

6. Set the format to "Mac OS X Extended (Journaled)." Click "Apply" to restore the bootable partition to the drive.

References

• MacWorld: Disk Utility's Hidden Talents
• Ken Stone: Formatting & Partitioning a Hard Drive in OS X