How to Reset an iMac to Factory Default

To reset an iMac to factory default, back up anything you need, erase the startup disk with Erase Assistant or macOS Recovery, and then reinstall or reactivate macOS. The correct method depends on the macOS version and whether the iMac has Apple silicon, a T2 Security Chip, or an older Intel processor.

Erasing an iMac permanently removes personal files, accounts, settings, and installed apps. Do not begin until you have copied every file you want to keep.

What should you do before resetting an iMac?

Complete these checks before you erase the iMac:

1. Back up documents, photos, and other important data with Time Machine or another storage device.
2. Open the Apple menu and select About This Mac to note the installed macOS version and basic hardware details.
3. Make sure you know the password for your Apple Account, formerly called an Apple ID, and the password for an administrator account on the iMac.
4. Sign out of iCloud when possible. Turning off Find My also removes the connection that can cause Activation Lock to appear later.
5. Sign out of services such as iMessage if the iMac will have a different owner.
6. Connect the iMac to a reliable power source and internet connection. A wired keyboard and mouse can help if Bluetooth accessories disconnect during the reset.

If the iMac is being passed to someone else, do not restore your backup after erasing it. Stop when Setup Assistant displays its first welcome screen.

How do you reset an iMac through macOS Recovery?

macOS Recovery is the built-in recovery system used to erase a startup disk and reinstall macOS. Use this method when Erase All Content and Settings is unavailable or macOS will not start normally.

1. Shut down the iMac.
2. On an iMac with Apple silicon, press and hold the power button until startup options appear. Select Options, then Continue.
3. On an Intel-based iMac, turn it on and immediately hold Command-R until the Apple logo, a spinning globe, or the Recovery window appears.
4. Enter an administrator password if requested.
5. Select Disk Utility, then Continue.
6. Select Macintosh HD under Internal. If the sidebar is incomplete, choose View and then Show All Devices.
7. Select Erase. Use the name Macintosh HD and the format recommended by Disk Utility, normally APFS. Choose Erase Volume Group if that option appears; otherwise choose Erase.
8. After the erase finishes, quit Disk Utility to return to the Recovery window.
9. Select Reinstall macOS, choose Continue, and follow the prompts. Select Macintosh HD as the installation disk when asked.

Do not erase external drives or disk images shown in Disk Utility. If you are unsure which entry is the internal startup disk, stop before confirming the erase.

How do you use Erase Assistant on a newer iMac?

Erase Assistant is the simpler method because it removes personal content and settings while keeping the installed operating system available. Erase All Content and Settings is available on supported iMac models with Apple silicon or the Apple T2 Security Chip running macOS Monterey 12 or later.

1. In macOS Ventura 13 or later, open the Apple menu and select System Settings.
2. Select General, then Transfer or Reset.
3. Select Erase All Content and Settings.
4. Enter the administrator password and review the items that will be removed.
5. Enter the Apple Account password if asked so Find My and Activation Lock can be turned off.
6. Confirm the erase and allow the iMac to restart.

On macOS Monterey 12, open System Preferences and choose Erase All Content and Settings from the System Preferences menu. If the option does not appear, use macOS Recovery instead.

What happens while an iMac is being reset?

The reset removes user accounts, personal files, network settings, and installed apps. Erase Assistant preserves the currently installed macOS system, while the Recovery method erases the startup volume and then downloads or installs macOS again.

The time required varies with the iMac, disk condition, internet speed, and macOS download. Keep the iMac powered on and connected to the internet throughout activation and reinstallation. Several restarts, a blank screen, and changing progress estimates can be normal, but repeatedly returning to an error screen is not.

What should you choose in Setup Assistant after the reset?

Setup Assistant is the first-start sequence that asks for the region, network, account, privacy, and migration choices. The correct choice depends on who will use the iMac next.

• For a clean personal setup, continue through Setup Assistant and choose not to transfer information when prompted.
• To recover your own files and settings, select the option to restore or transfer from a Time Machine backup or another Mac.
• If another person will receive the iMac, do not enter your Apple Account or create a new user. Shut down the iMac at the initial welcome screen.

Restoring a backup can return files, apps, and settings from the backup date. A clean setup avoids bringing old settings back, but it also means reinstalling needed apps and copying files manually.

What can you do if the iMac reset will not start or fails?

Try the action that matches the problem:

• If Recovery does not open, shut down fully and retry the correct startup method for Apple silicon or Intel.
• If a spinning globe or installer reports a connection problem, reconnect to a stable Wi-Fi or Ethernet network and try again.
• If Macintosh HD is missing, disconnect nonessential external devices, restart Recovery, and check Disk Utility again.
• If Disk Utility reports errors, select the internal disk and run First Aid before attempting another erase. Persistent disk errors may indicate that the iMac needs service.
• If Activation Lock requests an unfamiliar Apple Account, the previous owner must remove the iMac from that account. Erasing the disk does not bypass Activation Lock.
• If Erase Assistant mentions another volume or a Windows partition, remove that partition with Apple’s supported Boot Camp process before retrying.

Do not repeatedly erase unrelated volumes or use unofficial reset utilities. Those actions can make recovery more difficult without resolving an account lock or hardware problem.

How do you get official help resetting an iMac?

If the iMac cannot enter Recovery, cannot see its internal disk, repeatedly fails activation, or reports persistent storage errors, contact Apple Support. Open {site}, choose support for Mac, and describe the iMac model, macOS version, exact error message, and reset steps already attempted.

Apple may ask for proof of ownership when Activation Lock is involved. Apple Support or an authorized service provider can also help determine whether a failed erase is caused by the internal storage or another hardware component.