A major feature that debuted in Lion (OS X 10.7) and continues in Mountain Lion (OS X 10.8) is one I hope you’ll never need to use: recovery mode, officially called OS X Recovery. (It was called Lion ...

To restart an Intel Mac in Recovery Mode, hold Command+R when the computer restarts. For Apple Silicon Macs, press and hold the power button until startup options show on the screen. Recovery Mode ...

In the event of a serious problem with your Mac, you may need to reinstall your Mac operating system. There’s a simple way to do this using your Mac Recovery partition or via Mac Internet Recovery.