There might be some situations where Macbook or Macbook pro users may need to reinstall macOS Sierra. This can either be done as a troubleshooting technique only or for any other reaons that require them to reinstall Sierra as well.
Our method will re-install macos sierra without erasing the data or formatting your MAC hard disk. It will simply do a reinstall of mac OS sierra 10.12 system software. This approach will preserve your data, files, pictures, documents, apps, customisations, etc, while only reinstalling Mac OS only.
Please note, this tutorial is not for the clean install of mac os sierra. A clean install is different as it removes everything by erasing it and gives us a completely fresh machine with the latest mac os, just like it was factory reset or out of shop.
Also note, that we need to backup our mac (or macbook) before starting the process. Although the process is safe, it’s still recommended to have a complete backup of your files. So that if something goes wrong just in case, we’ll still be able to restore our MAC via time machine easily. MAC users should utilize this amazing utility more often and regularly backup their machine and data.
How to Reinstall mac OS Sierra
Once you’ve secured your files and system using time machine, now we’re ready for the steps to reinstall mac os sierra on macbook or any other machine running it.
Step 1: Back up your Mac (just ensuring!)
Step 2: Reboot the Mac device. Keep holding the COMMAND + R keys concurrently just as you hear the boot sound (this wil make our mac boot into the Recovery Mode)
Step 3: At the “macOS Utilities” screen choose “Reinstall macOS”
Step 4: Click on the continue button and go through the setup screen and the options that it shows.
Step 5: You will reach the screen where you’ll be asked to choose the Hard Disk drive for the mac OS sierra reinatall. Choose the disk labelled “Macintosh HD” or the any other name that you had given to your disk. The system recovery will re-install the OS in this disk drive.
You’ll need to click continue to proceed. If you use FileVault, then you might also need to click “unlock”.
Step 6: Sit back and wait for the reinstall process to complete. Your screen will turn black with Apple logo on it. There will be a progress bar under it which will show us the progress and an estimate of how much more time we might be needing to wait for complete mac os sierra reinstallation. The reinstall process can be faster or slower, based on your macbook specs or your disk status, etc. So have patience and let the process complete.
Once the reinstall process finishes, your mac device will reboot automatically. It will ask you to login to your account. Login using your user account and you will be able to login to the same environment with all data, applications, files, configuration, etc. being preserved.
Please note that you might feel an immediate “slow” mac os Sierra after the reinstall, but don’t worry, that’s just temporary as mac is running the background indexing process again. Once it’s complete, you won’t notice the slow spotlight, etc. on your mac after reinstalling the mac os sierra.
The reinstall process usually eliminates and fixes many issues that your OS might be giving. So it might be a good troubleshooting step to resolve the problems with macOS sierra, without losing any of your data