Reinstalling the Operating System

What does reinstalling the operating system mean?

The operating system (OS) is the single most important software on any computer. It is what enables all of the different hardware components in your machine to work together and runs the programs that you need. Software related issues are among the most common issues that afflicts Apple computers. While numerous other methods can be used to remedy them, reinstalling the OS is the most effective means of eradicating any software issues. It does have its drawbacks and is often used as a last resort because it erases any user data and applications from the computer. That means you should backup anything you would not like to be deleted on to an external drive or cloud network prior to performing a OS reinstall. The method to perform a reinstall depends on the model of computer you have and the OS you are currently using.


How to reinstall the operating system on an Apple computer

If your Mac has OS X 10.6 Snow Leopard installed, you will need a Snow Leopard retail disc. Otherwise, you can use the network recovery feature to restore the Mac.

  1. Power Down the machine. This can be done through the Apple Menu or by holding down the power button for 5 seconds.
  2. Locate the following keys on your keyboard:
    • OS X 10.6 Snow Leopard Users: Option Key
    • OS X 10.7 Lion or Later: Command (⌘) key and R key
  3. Turn on your Apple computer and hold down the key(s) noted in step 2 (based on the operating system) immediately after you hear the startup sound.
    1. For OS X 10.6 Snow Leopard Users, once the mouse pointer appears on the screen, insert the Snow Leopard disc and select it on the screen to continue.
    2. For OS X 10.7 Lion or later, you may be asked to connect to a wireless network to continue the process. Otherwise, the process will continue on its own.
  4. Follow the on-screen instructions to reinstall the operating system.