I've decided to reistall osx Mavericks on my MacBook, so I restarted my Mac clicking cmd ⌘+R. In recovery mode I erased the main hard drive so I can have a clean install.

Then I selected "Install OS X Maverics" and after asking my permission to "verify the installation with apple" I got this error:

An error occurred while preparing the installation. Try running this application again.

I restarted, and then it started the "Internet Recovery" mode, which now gives me the option to install OS X Mountain Lion instead of Mavericks, and gives me the same error every time.

I've checked the date through the terminal, and it is correct, but I am not in "PDT", I'm in "IDT" time zone.


4 Answers 4


I know it's late, but if anyone coming here for macOS 10.10+ I did the following:

Reset Drive

  1. Boot in recovery mode (Cmd ⌘ R)
  2. Select Disk Utility
  3. Choose Macintosh HD
  4. Verify Macintosh HD
  5. Erase Macintosh HD

Reset Mac time and PRAM

  1. Restart and hold Cmd ⌘ Opt ⌥ P R (Resetting PRAM as stated above)
  2. After second chime, hold Cmd ⌘ R to boot in recovery mode
  3. Select language
  4. Enter wifi information (or plug in ethernet cable)
  5. Select Utilities from the task bar
  6. Choose Terminal
  7. Enter date mmddHHMMyyyy where mm = two digit month, dd = two digit day, HH = 24 hour, MM = minute, yyyy = 4 digit year (time zone was incorrect for me, but didn't seem to matter)
  8. Exit Terminal (Cmd ⌘ Q)

Reinstall macOS

  1. Reinstall Mac OS X (or macOS)

It worked only after doing all of these.

Source: https://blog.macsales.com/31640-tech-tip-an-error-occurred-while-preparing-the-installation-fix

  • 1
    thank you sir! only all steps (date and recovery mode helped) Jan 6, 2018 at 0:17
  • OP should mark this as the answer, only thing that worked
    – mxmissile
    Aug 28, 2018 at 13:49

Only if you have a Recovery partition intact on the machine will it attempt to recover to the OS that was last installed, otherwise Internet Recovery will recover to the OS your machine shipped with -

If you use Internet Recovery to reinstall OS X, it installs the version of OS X that originally came with your computer. After installation is finished, use the Mac App Store to install related updates or later versions of OS X that you have previously purchased.

Ref: http://support.apple.com/kb/HT4718

  • 2
    Most probably Samuel erased the whole disk and its Recovery partition. Hence forcing an Internet recovery back to Mountain Lion.
    – dan
    Dec 29, 2014 at 18:54

Here are some steps to try and narrow down what is causing the problem:

  1. Try resetting the PRAM on your macbook. See http://support.apple.com/kb/PH14222?viewlocale=en_US for the steps to do this.

  2. Boot into recovery mode and verify the hard disk with disk utility. This will tell you if there is a problem with the disk itself.

When you erased your hard drive did you format it as Mac OS Extended (Journaled) for both the physical disk and the partition? (The partition is usually called Macintosh HD).

  • Try the magic PRAM to solve everything :). LoL !
    – dan
    Dec 29, 2014 at 18:55

I've had this problem a couple of time and resetting the PRAM definitely solved it.

First : Try resetting the PRAM on your macbook by pressing Cmd ⌘ Opt ⌥ P R When your mac's booting, at the chimes. When you hear the Chime sound for the second time, release it. http://support.apple.com/kb/PH14222?viewlocale=en_US for the steps to do this.

Then you have to Boot into recovery mode ( hold Cmd ⌘ R at the chimes) and verify the hard disk using disk utility. Verify and fix the disk if needed.

And also make sure that your hard drive was formatted as Mac OS Extended (Journaled) for both the physical disk and the partition.

That should fix the problem...

  • resetting the pram did not work for me
    – user150211
    Oct 4, 2015 at 0:44

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .