How to Install Mac Os X 10.9?

ARCHIVED: How do I Install OS X 10.9 (Mavericks)?

Click Reinstall OS X, and then Continue. Follow the instructions on the screen, and then choose your hard disk. Click Install, and enter your Apple ID information if prompted. When the installation is complete, select App Store... from the Apple menu, and install any available updates.

How do I Get OS X 10.9 on my Mac?

Download the Installer from Apple directly to the computer that you want to install the new OS X onto.
Take your computer into the nearest Apple Store and they will do the upgrade for you.
Make a USB thumb drive installer that you can plug into your computer to upgrade it.

Can you Still Download MacOS Mavericks?

Mavericks is not available in the Mac App Store, but you can download it if you downloaded it before. Go to one of the Mavericks machines, open the Mac App Store, click Purchases and see if it allows download of Mavericks. If so, download the installer but dont let it run.

How do I Install an Older Version of Mac OS X?

Start up your Mac pressing ShiftOption/AltCommandR.
Once you see the macOS Utilities screen choose the Reinstall macOS option.
Click Continue and follow the onscreen instructions.
Select your startup disk and click Install.
Your Mac will restart once the installation is complete.

How do I Install OS X Mavericks?

Install OS X Mavericks From the Bootable USB Flash Drive. Screen shot courtesy of Coyote Moon, Inc.
Boot From the OS X Mavericks Installer. Plug the USB flash drive that contains the Mavericks installer into one of the USB ports on your Mac.
Use Disk Utility to Erase the Startup Drive.
Start the Mavericks Install Process.