Otherwise, if you have Internet access, follow the instructions on this page to prepare the external drive and install OS X on it. If you already have an external drive with OS X installed, start up from it. If Step 1a fails because of disk errors, and no other Mac is available, then you may be able to salvage some of your files by copying them in the Finder.

You don't need a DVD if you're running OS X 10.7 or later.ī. Start up from the Recovery partition, or from a local Time Machine backup volume ( option key at startup.) When the OS X Utilities screen appears, launch Disk Utility and follow the instructions in this support article, under “Instructions for backing up to an external hard disk via Disk Utility.” The article refers to starting up from a DVD, but the procedure in Recovery mode is the same. You need an external hard drive to hold the backup data.Ī. There are several ways to back up a Mac that is unable to start. If you don't care about the data that has changed since the last backup, you can skip this step. If you want to preserve the contents of the startup drive, and you don't already have at least one current backup, you must try to back up now, before you do anything else. The first step in dealing with a startup failure is to secure the data. To restart an unresponsive computer, press and hold the power button for a few seconds until the power shuts off, then release, wait a few more seconds, and press it again briefly. Some of them may not be applicable to your model or your situation. Take each of these steps that you haven't already tried.

Mac el capitan update stuck at startup