HT201372: Create a bootable installer for OS X

Learn about Create a bootable installer for OS X
bfairbanks

Q: How do I get my computer to recognize this boot disk?

Hello,

 

I followed the instructions on how to create a bootable installer for OS X El Capitan. I set it up on a USB drive.

 

But how do I get my computer to recognize it as a bootable drive? If I go into System Preferences under Startup Disk, it is not listed there. If I restart the machine holding down the Option key, it doesn't give me an option to boot from this USB drive.

 

What do I need to do to get my machine to recognize it as a bootable drive?

 

The reason I'm trying to do this is so I can unmount the hard drive and run Disk Utilities. Is there an easier way to do that?

 

Thank you,

 

Bruce Fairbanks

OBS,iMac (24-inch Early 2008), OS X El Capitan (10.11.4)

Posted on Apr 30, 2016 4:51 PM

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Q: How do I get my computer to recognize this boot disk?

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  • by babowa,Helpful

    babowa babowa May 10, 2016 7:39 PM in response to bfairbanks
    Level 7 (31,893 points)
    iPad
    May 10, 2016 7:39 PM in response to bfairbanks

    Well, you can always use recovery mode: boot up with Command + R held down right after the chime. Hold keys until you see a progress bar. Will take a while to connect to Apple's servers. When you see a Utilities window, choose Disk Utility to check your drive.

     

    What is the problem with your drive?

     

    As for your USB stick: which instructions did you use? Did you format the thing first to it is bootable? I've not done this because I prefer bootable clones, so I can't be of specific help with this.

  • by bfairbanks,

    bfairbanks bfairbanks Apr 30, 2016 5:05 PM in response to babowa
    Level 1 (4 points)
    Mac OS X
    Apr 30, 2016 5:05 PM in response to babowa

    Thanks for the information. I didn't know about recovery mode. I just wanted to run Disk Utilities because my machine was running slow.

     

    I followed these instructions on how to create the bootable installer: 

    HT201372: Create a bootable installer for OS X

  • by babowa,Helpful

    babowa babowa May 10, 2016 7:40 PM in response to bfairbanks
    Level 7 (31,893 points)
    iPad
    May 10, 2016 7:40 PM in response to bfairbanks

    Running Disk Utility won't really help that; most of the time, that is the result of one/all of three things: incompatible third party software/plugins/AV software, and/or not enough RAM installed and/or not enough empty hard drive space.

  • by Eric Root,

    Eric Root Eric Root May 1, 2016 2:47 PM in response to bfairbanks
    Level 9 (70,061 points)
    iTunes
    May 1, 2016 2:47 PM in response to bfairbanks

    You can make a bootable USB stick to install using this free program which will do all the work for you.

     

    Bootable USB Flash Drive – Diskmaker X

  • by bfairbanks,

    bfairbanks bfairbanks May 10, 2016 7:42 PM in response to Eric Root
    Level 1 (4 points)
    Mac OS X
    May 10, 2016 7:42 PM in response to Eric Root

    Eric, thanks for the information.  I haven't heard of that program.  I'll give it a try!

     

    Bruce