To use Recovery Mode, follow these instructions: This can be used to install a fresh copy of Mavericks on your hard drive, provided you have Internet access. Use Recovery Mode Every Mac operating system since Lion (OS X 10.7) has included Recovery Mode, a special boot partition that enables you to recover from catastrophic failures and problems. But every once in a while you might want or need to - here are step by step instructions for making it happen. Most of the time you'll never have to worry about having to install a new operating system on your Mac - the one that's on there should work fine through thick and thin.
