How do I go about downgrading from Mavericks back to Mountain Lion? I do not have an installer as ML shipped with my Macbook.

Question

I would like to re-install ML as I have a few issues with Mavericks that really annoy me when I am using my Mac now. I just need to know how I can downgrade back into ML without having the installer file. I cannot reach it in the appstore or on my purchased list because I never actually had to buy it since it shippd with my Mac. Thanks for the help!!

Answer 1

Install Mavericks, Lion/Mountain Lion Using Internet Recovery
Be sure you backup your files to an external drive or second internal drive because the following procedure will remove everything from the hard drive.
Boot to the Internet Recovery HD:
Restart the computer and after the chime press and hold down the COMMAND-OPTION- R keys until a globe appears on the screen. Wait patiently - 15-20 minutes - until the Recovery main menu appears.
Partition and Format the hard drive:
1. Select Disk Utility from the main menu and click on the Continue button.
2. After DU loads select your newly installed hard drive (this is the entry with the mfgr.'s ID and size) from the left side list. Click on the Partition tab in the DU main window.
3. Under the Volume Scheme heading set the number of partitions from the drop down menu to one. Click on the Options button, set the partition scheme to GUID then click on the OK button. Set the format type to Mac OS Extended (Journaled.) Click on the Partition button and wait until the process has completed. Quit DU and return to the main menu.
Reinstall Lion/Mountain Lion. Mavericks: Select Reinstall Lion/Mountain Lion, Mavericks and click on the Install button. Be sure to select the correct drive to use if you have more than one.
Note: You will need an active Internet connection. I suggest using Ethernet
            if possible because it is three times faster than wireless.
This should restore the version of OS X originally pre-installed on the computer.