This should restore the version of OS X that came with the computer pre-installed.

Select Install OS X from the Utility Menu and click on the Continue button.

Quit Disk Utility and return to the Utility Menu. Set the Format type to Mac OS Extended (Journaled.) Click on the OK button and wait for the process to finish.

Set the partition scheme to GUID then click.

Click on the Erase tab in Disk Utility’s main window. After Disk Utility loads select the drive (usually, this is the out-dented entry with the mfgr.'s ID and size) from the side list.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. I have a 2013 Macbook Pro Retina 13' screen.

Hwo to clean the mac hard drive space