How can I reinstall macOS 10.11 El Capitan on my old 2009 MacBook Pro?

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Level 1

5 points

How can I reinstall macOS 10.11 El Capitan on my old 2009 MacBook Pro?

I was trying to wipe and reinstall El Capitan on my old 2009 MBP. Only to find out after I wiped it that the bootable external HD I had made years ago was no longer operational. Now I can not figure out to make a bootable usb drive to save my life. I have downloaded both an .iso and a .dmg of El Capitan from internet archive, but everytime I try to create the bootable USB in Terminal, I alway get the command not found error. I can not get the MBP to boot into anything other than OS X Utililites and it will only try to reinstall OSX from the internet and I keep getting the 403 error when it tries to verify and download from the Apple store. I feel like I am missing some really simple, yet really important step..... Any options out there or did I jus t brick this laptop?

[Re-Titled by Moderator]

Original Title: Help with reinstall of El Capitan on my old 2009 MBP.

MacBook Pro 15″, OS X 10.11

Posted on Sep 17, 2025 03:08 AM

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Answer 1

HWTech

Level 9

66,896 points

Sep 17, 2025 05:43 PM in response to ebyson

Use your OSX 10.6 Snow Leopard Upgrade DVD to install Snow Leopard.

Once Snow Leopard has been installed, you may possibly need to install the most recent update patch for Snow Leopard.

You can use any computer or OS which can access the Internet to download the macOS 10.11 El Capitan installer, then transfer that installer DMG file to this iMac where you can run the .pkg file to extract the real installer to the Applications folder where you can launch the real installer to upgrade to El Capitan.

Here is an Apple article with links to various macOS installers and special instructions for using the older (10.7 to 10.12) installers:

How to download and install macOS - Apple Support

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