There could be several reasons why you would consider erasing or reinstalling your MacOS. You might want to sell it or maybe just want to give a fresh start to your system. Do it wrong, and you could land yourself in huge trouble.
For instance, suppose you are considering selling your MacBook to a total stranger. In that case, you need to make sure that the new owner can’t access your files. Or, if you want to wipe off your system just so it can be as good as new, you need to make sure that you don’t lose any important files or data.
So, before you start the erasing and reinstalling process, make sure that you have transferred your files to an external storage drive or create an online backup for everything. You can either use the time machine or iCloud to serve your purpose. After you are done with that, here’s a quick run-through of the steps to help you throughout the reinstalling and erasing process.
Try to boot from Recovery Mode
You might not know this, but your system’s Recovery Mode is a treasure trove of some valuable tools. Plus, it is one of the easiest ways to wipe MacOS from scratch. For this, you need to shut down your system and turn it on again like you usually do. But this time, you need to hold down Command+R. And your system will start booting in the recovery mode.
But if you have an older version of macOS (from 2010 or earlier), you might not be able to use Recovery Mode. For such older systems, you need to hold “Option” while the system starts the booting process. After this, you need to click on “recovery partition.”
Wipe off your hard drive
If you want your macOS to be clean as it was when you first bought it, you need to get rid of all your data and files from your system. This means that you have to wipe off the hard drive of the system.
Suppose you are planning to reinstall and erase your operating system partially by keeping your files in place. In order to wipe away your hard drive, you need to start the process by clicking on the Disk Utility option. There should be a long list of hard drives on your computer’s screen. Now click on the primary drive and then select Erase. Your entire information on your system will ultimately be wiped off.
Pro Tip: You should always be prepared for the worst and have your files backed up thoroughly.
Reinstall macOS
After you are done with the erasing part, you now need to get ready to reinstall the new macOS. For this, you need to click the “Reinstall macOS” button.
After this, your system will ask you about the hard drive where you want to install the new operating system. Select the one you feel is suitable, and you are all done.
Lastly,
Your system will now begin reinstalling your MacOs. It might take a few minutes for your system to finish the process. You’ll know the process is finished when your system restarts and asks to create an account. If you are selling your system, shut it down at that point. The new user will create his own account. But if you are planning to use it, you can log into your account and start using your system.