Looks like no one’s replied in a while. To start the conversation again, simply ask a new question.

User profile for user: lonkelo
lonkelo Author
User level: Level 1
9 points

Cannot re-install El Capitan on iMac Late 2009

I've decided to give my old iMac Late 2009 to my dad. I decided to wipe it and reinstall it with El Capitan, but seem to have got stuck.


Upon restarting I get the following options (I'm translating this from Dutch, so it might not be exactly what you'd expect in the English version):

  • Reset with Time Machine
  • Re-install OS X
  • Find information online
  • Disk Utility


Disk Utility shows the following:

Internal

> WDC WD5000AAKetc. Media

>> Which contains the Macintosh HD --> I wiped this and called it Macintosh HD and set the structure to OS X extended (journaled)


Disk Copies

> Apple Disk Image Media

>> OS X Base System


  1. When I select 'Re-install OS X' I get to choose a disk on which to install it.
  2. I picked Macintosh HD
  3. I login with my AppleId
  4. Upon which I get the message: 'This item is temporarily unavailable. Try again later.'
  5. I had a feeling this might not be temporary, so I decided to make a bootable USB drive instead
  6. I downloaded the InstallOS.pkg on my MacBookAir (M1, 2020)
  7. But when trying to install the .app, which I need to put on the USB drive, I get the message: 'This version of OS X 10.11 cannot be installed on this Computer'.


At this point I'm stuck. Any ideas for me to get El Capitan on the old iMac again?


Thank you very much for taking the time to read this!

Posted on Jun 1, 2021 1:49 AM

Reply
Question marked as Best reply
User profile for user: Eau Rouge
Eau Rouge
User level: Level 8
42,554 points

Posted on Jun 1, 2021 2:55 AM

If you try to reinstall El Capitan from Apples Recovery Servers you may encounter the issue that Apple still have not updated the certificates of the OS's on their servers, they expired on October 2019, so Apple have been extremely tardy not to address this.


However there is a workaround,


We are going to set the time and date on your mac to a date previous to the expiry date of the certificates.


Connect your mac to your router via cable, not WiFi


Boot to your Recovery HD, click on Utilities in the menubar select Terminal.


Make sure WiFi is switched off, it can reset the date back to today.


Enter a new date, for example or just copy and paste


sudo date -u 011421002017


press Return

enter your password

press Return


If Terminal returns an error saying sudo : command not found, then try again without sudo.

just enter 


date -u 011421002017


press Return


You won't be prompted for a Password if you did not need to use sudo


Once the date has changed you can quit Terminal.


Now try downloading the OS.

Click on Install OS X, press Continue.


If this works then when the OS is installed and booted up you can Open System Preferences> Date & Time

and reset the time back to today.


++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++


If resetting the date does not work then you may have to revisit downloading the InstallMACOSX.dmg.

Another brilliant piece of Apple software engineering that in order to develop the .dmg

to the Install OS X El Capitan.app that you need if you want to install El Capitan and create a bootable USB installer

requires you to be using a mac that is capable of running El Capitan.

The mac you tried with previously more than likely came preinstalled with an OS newer than El Capitan and that is

why it refused to do it. Unless you have another mac that you know can run El Capitan you may want to try this workaround.


(Incidentally your post says InstallOS.dmg, this contains the installer for macOS Sierra 10.12.6 which cannot be installed

on a 2009 iMac anyway, you need to download the correct one for El Capitan.)


https://apple.stackexchange.com/questions/379603/how-do-i-create-el-capitan-installer-on-a-catalina-or-post-el-capitan-installe

View in context

Similar questions

8 replies
Question marked as Best reply
User profile for user: Eau Rouge
Eau Rouge
User level: Level 8
42,554 points

Jun 1, 2021 2:55 AM in response to lonkelo

If you try to reinstall El Capitan from Apples Recovery Servers you may encounter the issue that Apple still have not updated the certificates of the OS's on their servers, they expired on October 2019, so Apple have been extremely tardy not to address this.


However there is a workaround,


We are going to set the time and date on your mac to a date previous to the expiry date of the certificates.


Connect your mac to your router via cable, not WiFi


Boot to your Recovery HD, click on Utilities in the menubar select Terminal.


Make sure WiFi is switched off, it can reset the date back to today.


Enter a new date, for example or just copy and paste


sudo date -u 011421002017


press Return

enter your password

press Return


If Terminal returns an error saying sudo : command not found, then try again without sudo.

just enter 


date -u 011421002017


press Return


You won't be prompted for a Password if you did not need to use sudo


Once the date has changed you can quit Terminal.


Now try downloading the OS.

Click on Install OS X, press Continue.


If this works then when the OS is installed and booted up you can Open System Preferences> Date & Time

and reset the time back to today.


++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++


If resetting the date does not work then you may have to revisit downloading the InstallMACOSX.dmg.

Another brilliant piece of Apple software engineering that in order to develop the .dmg

to the Install OS X El Capitan.app that you need if you want to install El Capitan and create a bootable USB installer

requires you to be using a mac that is capable of running El Capitan.

The mac you tried with previously more than likely came preinstalled with an OS newer than El Capitan and that is

why it refused to do it. Unless you have another mac that you know can run El Capitan you may want to try this workaround.


(Incidentally your post says InstallOS.dmg, this contains the installer for macOS Sierra 10.12.6 which cannot be installed

on a 2009 iMac anyway, you need to download the correct one for El Capitan.)


https://apple.stackexchange.com/questions/379603/how-do-i-create-el-capitan-installer-on-a-catalina-or-post-el-capitan-installe

Reply
User profile for user: lonkelo
lonkelo Author
User level: Level 1
9 points

Jun 1, 2021 3:13 AM in response to Eau Rouge

Thanks a lot for the in-depth answer, but apparently you cannot get into recovery mode on an iMac that is older than mid 2010: https://recoverit.wondershare.com/mac-data-recovery/boot-into-recovery-mac.html.


It appears that I need a grey recovery disk for this. Since I myself got this iMac second hand from university, I didn't get this disk with it.


Does anyone know where one could find an image of this disk?


Reply
User profile for user: PRP_53
PRP_53
User level: Level 10
85,609 points

Jun 1, 2021 2:10 AM in response to lonkelo

I am not certain the iMc from 2009 can boot into Recovery Mode Command + r keys immediately at restart. If it can - strongly suggest connecting it via Ethernet Cable to Router. This will eliminate Wifi and give a faster and reliable Internet connection. Chose Install macOS and if it work, it should bring down the El Capitan Installer and start the installation.


If the iMac can not start from Recovery Mode and connect to internet - these three key, Command + Option +r also immediately at startup and Ethernet Cable connection. This is Internet Recovery Mode and Apple Globe will appear and once full loaded - same process - choose Install macOS.


The last portion you described - the new M1 computer make have downloaded the El Captain DMG but can do nothing with it. That is because the computer is too new and Apple will not allow an old macOS to function on a computer that has not and can not run the Old OS.


If you have access to a computer Compatible with El Capitan you might be about to transfer the El Capitan DMG to that computer and create the desired Bootable Installer of El Capitan.

Reply
User profile for user: Eau Rouge
Eau Rouge
User level: Level 8
42,554 points

Jun 1, 2021 3:50 AM in response to lonkelo

What makes you think that you cannot boot into Recovery HD, have you tried.

restart your mac press and hold Command and R keys.

Your second paragraph in your first post indicates that you were booted to the Recovery HD

when you erased your mac and tried to reinstall

I am using a 2008 Mac Pro and it has a Recovery HD, so give it a go.


Macs of that era came with two grey install DVDs, these DVDs were only for that

particular model of mac, so it is very difficult to locate the exact disks for the exact

mac you have online as most resellers are a bit vague over that.


You could buy the white official retail copy of the Mac OS X Snow Leopard DVD

which will install version 10.6.8 to your mac, then you would need to update it to

version 10.6.8 from this link, https://support.apple.com/kb/DL1399?viewlocale=en_US&locale=en_US

Then you would be able to create that bootable USB for El Capitan.


Have you tried the workaround to create the bootable USB on your other mac.

Reply
User profile for user: lonkelo
lonkelo Author
User level: Level 1
9 points

Jun 1, 2021 2:56 AM in response to PRP_53

Thank you for the speedy answer!


I've tried what you've suggested, but to no avail. I've connected the machine to the modem via ethernet, but the ethernet connection is not visible under the network button top right, whereas my wifi network (and loads of others) are visible. Note that if I connect to my wifi, it does allow me to log into my Apple account. So that should be working, albeit slower?


Then there is the issue that pressing Command + Option + R won't get me to a screen showing the Apple Globe. I just get the Apple logo with a loading bar, which brings me back to the same four options as outlined above:

  • Reset with Time Machine
  • Re-install OS X
  • Find information online
  • Disk Utility


EDIT: I've looked up Internet Recovery and saw that it's only supposed to be available on machines after 2012: https://recoverit.wondershare.com/mac-tips/internet-recovery-mac-not-working-mac.html. I guess it doesn't work on the iMac because it's from 2009?




Reply
User profile for user: lonkelo
lonkelo Author
User level: Level 1
9 points

Jun 1, 2021 6:41 AM in response to Eau Rouge

Yes, you're right. I got confused with the internet recovery mode. Anyway, I opened the terminal and changed the date. I get a new error when trying to re-install El Capitan. As before I get a prompt informing me that Apple is checking whether my computer can run El Capitan. I get an error message after this that 'An error has occurred while preparing the installation. Re-execute this program.'


The internet connection via ethernet does appear to work after all. It just doesn't say so anywhere, but verification of my Apple ID does work.


The newer fix from Apple Stackexchange does not work, since there are no downloads available after registering on VMWare. The original answer has helped me create a bootable USB drive with El Capitan, however, and this has helped me re-install El Capitan! Brilliant!


Thanks a lot for the patient and in-depth answer!

Reply

Cannot re-install El Capitan on iMac Late 2009

Welcome to Apple Support Community
A forum where Apple customers help each other with their products. Get started with your Apple ID.
Learn more Sign up