If you need to erase your startup disk, follow these steps. On a rare occasion your Mac may have a virus or a piece of Malware.Įrasing your startup disk permanently deletes all of the data stored on it.You need to give the Mac to another colleague and it needs to be clean from old data.You need to give the Mac back to HardSoft.The macOS installer says that it can't install on your computer or volume.You're trying to resolve an issue that Disk Utility cannot repair.You should erase your startup disk in the following circumstances. When you see the macOS Utilities window, continue to the next section to determine whether to erase your machines hard drive or begin installing macOS.ĭecide whether to erase (format) your startup disk before installing macOS. This combination requires macOS Sierra or later. Install the macOS that came with your Mac, or the version closest to it that is still available. Upgrade to the latest macOS that is compatible with your Mac. Install the latest macOS that was installed on your Mac, without upgrading to a later version. Release when you see the Apple logo or a spinning globe. Hold down one of the following combinations immediately after pressing the power button to turn on your Mac.

The Recovery installs different versions of macOS depending on the key combination you press while starting up.

Os x utilities macbook pro