Installer reports "OS X could not be installed on your computer" or "This disk cannot be used to start up your computer"

Learn what to do if the installer reports "OS X could not be installed on your computer" or "This disk cannot be used to start up your computer".

When installing OS X, the installer may report one or more of the following:

  • A message appears, "Install Failed: OS X could not be installed on your computer. OS X can't be installed on the disk Macintosh HD because a recovery system can't be created. Visit to learn more."
  • The installer log shows the message, "Recovery system creation failed with error -69713 (The booter/recovery partition must be grown by a larger amount)."
  • You may be presented with an option to select which disk is the target for installation. In some situations, the disk you want to upgrade may be labelled "This disk cannot be used to start up your computer."

If possible, back up and reformat the target disk before installing.

If you aren't able to back up and reformat, try the following steps to resize the partition where you want to install OS X: 

  1. Restart your Mac from your usual startup disk.
  2. Open Disk Utility, located in /Applications/Utilities/ .
  3. Select the disk where the volume you intend to upgrade resides. This usually starts with a number representing the total size of the disk.

  4. Click the Partition tab.

  5. Click and drag the resize corner of your intended install partition to make the size slightly smaller.

    The blue portion represents used data space. The partition only needs to be approximately 128MB smaller than it was before resizing but it needs to be larger than the blue portion.


    Before:    After: 
  6. Click Apply.

  7. When the partition resizing is complete, quit Disk Utility and install OS X.
  8. After the OS X installation is complete, you can use Disk Utility to resize the partition back to its original size by dragging the resize corner to make the partition as large as it was before.


Published Date: