I accidentally started up an OS Installer image on my original main Snow Leopard partition. I don't have a DVD inserted for installer. My external hard drive was disconnected during the this time. Yes, Disk Utility attempts to repair it three times, but it fails, while the FSCK test passes without a hitch. If you need anymore help in regards to this please contact us here.Yes, there was a space in '/sbin/mount -uw /' - I typed it incorrectly in the previous post. If you're keeping your Mac, complete the setup assistant with your own information.If you erased your disk before installing, or you installed on an external drive or other new disk, your Mac restarts to a setup assistant. Your Mac restarts after installation is complete. To verify eligibility to install macOS, your Mac serial number is sent to Apple, and you might be asked for your Apple ID. If you don't see it, click Show All Disks. Click Continue, then follow the onscreen instructions.

Choose Reinstall macOS (or Reinstall OS X) from the utilities window.You're now ready to install macOS.įollow these steps after starting up into the recovery agent: When done, quit Disk Utility to return to the utilities window.Click Erase to begin erasing your disk.Select your device or volume in the sidebar of Disk Utility.Select Disk Utility from the utilities window of macOS Recovery, then click Continue.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 boot disk utility