



The computer will begin to boot into the MacOS Recovery mode.Restart your Mac and hold down the following button combination:.We are assuming you already copied all your data to an external backup, or to your new Mac, because the following steps will really erase your disk. We are erasing a 2014 MacBook Air running MacOS 10.12 Sierra, but the steps will be similar with any recent Mac. Steps may vary with different version of macOS, and hardware configurations but the general idea is the same. Budget at least an hour for this process, slower Internet connections and older hardware will take longer. A Wi-Fi network with an active Internet connection.Erasing your storage drive and performing a fresh install using macOS Recovery This is much quicker than rewriting that disk space with blank data, and it also gives you a chance to recover accidentally deleted files with handy recovery software. We recommend erasing the drive with Apple’s Disk Utility keep your personal data safe. Instead, the reference to the file is removed from the file system (which keeps a list of all the files on your computer), so the computer is able to write new information in the same physical area when space is needed. When you empty your trash bin on your Mac, the files are not really erased. Why you need to erase your hard drive/SSD
