When downloading OS X El Capitan, I attempted to select the hard drive as the disk to install. Received message "This disk doesn't use the GUID Partition Table scheme". I followed the instructions and I am unable to change this setting Disk Utility. The selection for options is greyed out and unavailable. I don't understand what to do now.
MacBook Pro, OS X Yosemite (10.10.5)
Hello there, JackieLW80.
From what you're describing, you are unable to install Mac OS X El Capitan due to an error that states "This disk doesn't use the GUID Partition Table scheme". The following Knowledge Base article offers up some great information and guidance for troubleshooting install issues:
"You cannot install Mac OS X on this volume..." alert in Installer - Apple Support
To install Mac OS X on the disk, you must partition the drive to match the native partition scheme for your computer's processor type (Intel or PowerPC). Partitioning splits the disk into two or more volumes (though you can choose just one partition to resolve this particular issue, as described below).
Important: Partitioning erases the contents of the drive. Additionally, simply erasing the drive without partitioning will not resolve the issue (see Additional information, below).
Follow these steps:
- Back up your important data. Partitioning a hard disk erases all data on the disk.
- Open Disk Utility:
- If you're started from a Mac OS X installation disc, choose Disk Utility from the Utilitiesmenu.
- If you're started from your computer's Mac OS X volume, open Disk Utility from the Utilities folder. You can get there by choosing Utilities from the Finder's Go menu.
- Select the disk you want to partition (that is, the disk you want to install Mac OS X on. The disk contains size and model number of the drive, not "Macintosh HD" or a name you chose.
- Click the Partition tab in the Disk Utility window. If the partition tab is not visible, make sure you've selected the disk (not volume) in the left side of the window.
Tip: In Disk Utility, volume names are indented on the left side of the window. Disk names are not indented.- Choose the desired number of partitions from the Volume Scheme pop-up menu. It's OK to choose "1 Partition" if you only want one.
- Click Options.
Note: On some Intel-based Macs, the Options button does not appear under the partition tab. Use the erase tab to erase the disk instead. This will change the partition scheme to the default "GUID Partition Scheme". You can then use the partition tab to create additional partitions if desired.- From the Partition Scheme pop-up menu, choose "GUID Partition Scheme".
- Click OK.
- Make any other changes you wish in the Volume Information section, such as partition size(s) or naming.
- Click the Partition button to erase your disk and install the new partition scheme.
- When partitioning finishes, you should be able to install Mac OS X on the volume. Afterwards, you can restore backed-up data.
Additional information
Installer refers to the volume, but the issue is actually with the entire hard disk (specifically, with its partition scheme). That's why erasing the volume without re-partitioning the disk will not resolve the issue. Use Disk Utility as noted above to repartition the disk, using the GUID partition scheme.
Intel- and PowerPC-based Macs have different native partition schemes. The Mac OS X installer keeps you from selecting a hard disk that uses a different partition scheme (or any volumes on that disk) for installation. You can still use such disks for other storage purposes, swapping the disk back and forth between Intel- and PowerPC-based Macs if desired.
Thanks for being a part of Apple Support Communities.
Kind Regards.
When downloading OS X El Capitan, GUID partition error
