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OS X Error – An error occurred while preparing the install

Sometimes the most difficult issues have the simplest solutions. My current situation with a MacBook Pro just happens to be one of those situations.  When trying to reinstall OS X, getting error message “An error occurred while preparing the installation. Try running this application again”.  In this case, I was handed the MacBook Pro by a client because it would not completely boot up, not even after trying all of the keyboard boot up functions (like holding shift key on boot up). So the decision was made to reinstall Mac OS X Maverick (which is what was installed on it), using the Mac Disk Utility.  Simple enough, except for the fact that every time I tried to do the reinstall, I kept getting the error and the reinstall would not complete.  The following steps are what I discovered in order to fix the error, so that the reinstall can complete.

Fixing The Reinstall Error

  • Log In to the Mac Disk Utility screen by holding down “Command Key” + S during boot.  Select “Reinstall OS X” and hit continue


  • When you start the reinstall you will get a message about verifying eligibility with Apple. Hit continue


  • If you are going to get the error, this is the point where it will come up. Unfortunately, Apple gives you a seriously vague message “An error occurred while preparing the installation”. That message does NOT explain what went wrong.


  • From this point, click on Utilities –> Terminal


  • When the terminal window opens, type date and hit enter. What you will notice is that the date listed will be wrong.  That wrong date is what is causing the reinstall error.


  • To correct the wrong date –>  type date followed by MMDDHHMMYYYY  (Month – Date – Hour – Minute – Year)


  • At this point just exit the Terminal box and try to run the reinstall again

These steps should now correct your install issue with OS X.

4 thoughts on “OS X Error – An error occurred while preparing the install

  1. This helped me today with an older Macbook Air. Thank you for posting this!

    1. Glad it was able to help.

  2. Great tip! Help me with a MacBook Air

  3. Extremely helpful. I would never have worked out the error

    Many thanks


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