Before selling your device to someone else, if you wish to ensure the complete deletion of data then you need to restore Mac to factory settings. Factory reset will erase all the data stored on your hard drive and information stored in the system’s memory. Also, it will restore your device to its original configuration and settings.
But, your Mac has a special type of memory, called NVRAM or nonvolatile RAM that stores certain settings so that OS X can access quickly those. Moreover, each time you shut down or restart your Apple iMac, it flushes remnants of operating system, some content of its memory and software procedures to NVRAM. Thus, a simple OS X Recovery to the original configuration is not enough; you also need to perform NVRAM reset.
NVRAM also stores certain iMac’s startup settings, thus when you perform the NVRAM reset and reboot your computer, even these settings will restore to its factory defaults. Thus, performing OS X recovery along with NVRAM is the only way to reset Mac to factory settings.
Restoring Mac to factory settings using NVRASM Reset is easy to perform. After the reset, you need to reboot your iMac and use the built-in OS X recovery tool to finish the procedure of iMac factory restore.
- Open the Apple menu
- Choose “Restart.”
- That will open a dialog box with a one-minute countdown timer
- Before the countdown finishes, you need to confirm the restart or cancel the restart.
- If you don’t click ‘Cancel’ and the timer counts down to zero, then your device will automatically restart.
- Once the iMac restarts, press the “Command + Option + P and R” keys together before a grey screen appears on the monitor.
- Continue pressing the four-key combination till your device chimes, restarts again and chimes once again.
- When the device chimes for the second time, release the keys and let your iMac finish the restarting.
With these steps, you reset the settings of Nonvolatile RAM back to its default or original settings. After NVRAM reset, next you need to perform the OS recovery to erase the data stored on your system’s hard drive and to reset the other settings and configuration to the factory defaults.
How to Restore Mac to factory settings With OS X Recovery?
The iMac OS X Recovery feature will completely erase your hard drive and reinstall a fresh copy of OS X. That will return your device to its factory settings. The process needs the high-speed Internet connection. Thus, in the beginning, you need to confirm the availability of active Internet connection to your computer.
- Open the Apple menu
- Choose “Restart.”
- Again the one-minute countdown timer will appear. If you wish to cancel the restart, then you need to do it within this one-minute. After the countdown, the iMac will reboot automatically.
- Once, the device restarts, press the “Command” and “R” keys simultaneously
- Continue pressing the keys till your monitor displays a grey screen and the Apple logo appears.
- Once the logo appears, release the keys and the iMac will once again reboot
- This time the iMac will reboot the Mac OS X Utilities window
- Here, click on the ‘Disk Utility’ option
- Then, click on the ‘Continue’ button located at the bottom of the window
- A new dialog box will appear to inform you that a confirmation message will be sent to Apple
- Here also click on the ‘Continue’ button
- After the system confirmation, you will get a window with a set of options
- Here, select ‘Disk Utility.’
- Then, you will view a list of available drives and partitions
- From the list, select your startup disk
- Then, switch to the ‘Erase’ tab.
- Now, set the format to Mac OS Extended (Journaled)
- Rename your startup disk
- Then, click on the ‘Erase.’
- Enter your Apple ID and password on being prompted.
- Then the installer will download the needed data and start the reinstallation.
Once the reinstallation finishes, reboot your computer, but prior to that you need to take care of one more thing. After an NVRAM reset and restoring Mac to factory settings by using OS X Recovery, your iMac may lose track of your startup disk, and this can cause startup problems. To avoid such problems, choose “System Preferences” under Apple menu, and then under System group, select Startup Disk.’ Here, reselect your startup disk by clicking its icon. That is how your iMac will identify your ‘Startup Disk’ and you won’t face any startup problems.
That is how you can restore Mac to factory settings, and your device will get back to the factory defaults. It will have all the original settings and configuration that your device had when you newly bought it. Also, all the data on the hard drive will get completely erased.