How to restart original iOS on 2015 iMAC

Need to restart original iOS after clean out, used "Command+R" and took it too far. Folder with ? on the screen. I have two iMac PCs model # A1418 with chance to donate instead of trashing. What do I need to do?

iMac 24″, macOS 26.6

Posted on Aug 23, 2026 11:30 AM

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Question marked as Top-ranking reply

Posted on Aug 23, 2026 12:16 PM

You can use Internet Recovery Mode (Command + Option + R) to access the online macOS installer.


Here is an Apple article:

How to reinstall macOS - Apple Support


Here is an Apple article for properly preparing a Mac for sale:

What to do before you sell, give away, trade in, or recycle your Mac - Apple Support


FYI, if your Mac utilizes an internal Hard Drive or Fusion Drive, then the Apple instructions I linked are not sufficient to ensuring your personal data has been wiped since Apple's instructions assume a singe internal SSD, or a system that has FileVault enabled. If an internal Hard Drive is involved, then you either need to first enable FileVault & let the encryption process finish before using Disk Utility to perform a simple erase of the Hard Drive/Fusion Drive.


Or you need to use the "secure erase" feature in Disk Utility when erasing the internal Hard Drive (will break the Fusion Drive if equipped).....there is a separate button in Disk Utility's "Erase" section which offers a "secure erase" option of writing zeroes to the entire drive. If you do this with a Fusion Drive, then if you want to reinstall macOS, then you will first need to recreate the Fusion Drive after erasing the Hard Drive portion.


2 replies
Question marked as Top-ranking reply

Aug 23, 2026 12:16 PM in response to MikeinTiny

You can use Internet Recovery Mode (Command + Option + R) to access the online macOS installer.


Here is an Apple article:

How to reinstall macOS - Apple Support


Here is an Apple article for properly preparing a Mac for sale:

What to do before you sell, give away, trade in, or recycle your Mac - Apple Support


FYI, if your Mac utilizes an internal Hard Drive or Fusion Drive, then the Apple instructions I linked are not sufficient to ensuring your personal data has been wiped since Apple's instructions assume a singe internal SSD, or a system that has FileVault enabled. If an internal Hard Drive is involved, then you either need to first enable FileVault & let the encryption process finish before using Disk Utility to perform a simple erase of the Hard Drive/Fusion Drive.


Or you need to use the "secure erase" feature in Disk Utility when erasing the internal Hard Drive (will break the Fusion Drive if equipped).....there is a separate button in Disk Utility's "Erase" section which offers a "secure erase" option of writing zeroes to the entire drive. If you do this with a Fusion Drive, then if you want to reinstall macOS, then you will first need to recreate the Fusion Drive after erasing the Hard Drive portion.


How to restart original iOS on 2015 iMAC

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