Select Disk Utility from the Utility Menu and click on the Continue button.

Wait patiently - 5-15 minutes - until the Utility Menu appears.

Restart the computer and after the chime press and hold down the Command-Option-R keys until a globe appears.

Install Lion Through Yosemite on a New HDD/SDD Your model did not come with restore DVDs. I'm still running 10.8.5, I believe that's Mountain Lion. How can I get this great computer back to it's original state. I've deleted a lot of useless stuff but I cannot figure out what is taking up so much space on the hard drive. I do not have the original start up disks, I know I should but I don't as I have literally been traveling around the world since I bought the computer and have no idea as to where these disks could be. I don't use the computer for anything but, e-mail, surfing, and I use Logic for music, but I have all of the music on an external drive, so if I cleaned the drive I certainly wouldn't lose much. I actually have no idea as to the amount of junk that is on my computer just taking up space, but it's running a little slow so I was thinking of just completely clearing the SSD and starting from square one again. I have about 12 gigs available on the 120 gig SSD. After the installation process completes, your iMac will automatically reboot into OS X Mountain Lion.I have a 2013 Macbook Pro Retina 13' screen. For example, choose the hard drive you want to reinstall the operating system on and enter your Apple ID and password when prompted. The OS X Utilities window re-appears.Ĭhoose 'Reinstall OS X' and click 'Continue.' Follow the directions to reinstall OS X Mountain Lion. Open the 'Disk Utility' menu and choose 'Quit Disk Utility' after the system displays the message that the disk has been successfully erased.

The time for the process to complete depends on the amount of data on the disk.

Click the 'Erase' tab.Ĭlick the 'Format' pop-up list and select 'Mac OS Extended (Journaled).' Enter a name for the hard drive in the Name box and click 'Erase.' The system automatically erases the disk. If you only have one hard drive, it will be the only disk available. If the system does not automatically connect to the Internet, select your wireless network from the Wi-Fi menu to establish a connection.Ĭhoose 'Disk Utility' from the list of options to open the Disk Utility window and click 'Continue.'Ĭhoose the hard drive you want to clear.

Release the keys after the OS X Utilities window opens. Press the 'R' and 'Command' keys simultaneously and hold them when the system restarts.

Clean up hard drive mac