I Updated to el Capitan OS X but it will not install and I don't know how to go back
Macmini 6,1
Boot ROM Version MM61.0106.BOA
SMC Version (system) 2.7f0
Hardware UUID 9BFD0855-CE77-5E50-B023-F8F06B77B34C
Message reads OS X could not be installed on your computer
FIle system verify or repair failed
Quit the installer to restart and try again - Which I have done numerous times
See:
How can I uninstall OS X Yosemite and return to OS X Mavericks?
However, that error message may indicate that your HD is damaged and needs to be replaced.
- Boot to Recovery and repair the startup disk
OS X: About OS X Recovery - Apple Support
- If it is repairable reinstall the OSX
How to reinstall OS X on your Mac - Apple Support
Noting should be lost
- If you do not have a backup use disk utility to restore the internal disk to an external disk so you can try to recover data.
Then format the startup disk and do a fresh install of OSX
If not repairable then replace the HD
The first thing the installer does is check the drive’s integrity and yours not only failed but the installer was unable to repair the drive. Restart in the recovery partition, run Disk Utility and attempt to repair the drive there. It sometimes will even when the Installer’s diskcheck run fails. If DU reports failure then follow IIIaaass’s advice to format the drive and then boot in Internet Recovery mode to download and install the OS. Then you can use your backup during the setup process to move your data and applications. If DU reports success try running the installer again.
How do I take Mac mini back to Yosemite
