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A longtime Windows truism proposes that you need to reinstall the operating system often for best performance. But while there are times when it’s appropriate to do so, it’s not as vital a step as some propose.
As a Mac user, you might be curious if it’s the same case for macOS. Do you need to reinstall macOS regularly, and why should you ever reinstall the OS? Let’s dig into this question and the reasons behind it.
Do You Ever Need to Reinstall macOS?
Before we get into the motives for doing so, we should be clear that yes, there are some good reasons to reinstall macOS. However, this doesn’t mean that reinstalling it regularly is necessary.
macOS is a stable operating system that takes pretty good care of itself. Most users can use the copy of macOS that came with their system for years and never experience any problems. This is especially true since Apple introduced System Integrity Protection in OS X El Capitan, which limits user access to protected system files.
When you have a problem on your Mac, reinstalling the OS should be near the bottom on your list of troubleshooting steps. Let’s look at some situations where reinstalling macOS is a good idea, plus alternative ways to deal with these problems first.
1. When Your Mac Has a Serious Problem
The main reason most people would reinstall macOS is because their system is completely messed up. Maybe error messages pop up constantly, software won’t run correctly, and other usability issues prevent you from working normally. In extreme cases, your Mac might not even boot.
While rare, this is more likely to occur with power users who regularly play with new software and make tweaks to system settings. However, it can happen to anyone.
If your Mac has a major issue like this, we recommend first trying some other troubleshooting tools. Have a look at our list of the best free tools to fix common macOS problems for lots of help.
For example, you can use the built-in Disk Utility tool to check for errors with your storage disk. Apple also provides diagnostic tests to help you check for hardware failures. And third-party customization tools like OnyX offer easy maintenance utilities for when something goes wrong.
If these don’t fix your problem, proceeding with a macOS reinstall is a good idea.
2. When Your Mac Is Really Slow
Even if your Mac doesn’t have a critical problem, it might still run at a snail’s pace. When this happens, we first recommend reviewing common mistakes that slow your Mac down. You might need to remove some startup programs, run updates on your system, or clean out your storage drive to fix this issue.
But if none of these fixes have an effect, reinstalling macOS can likely help speed up your system. This is especially the case if your Mac is approaching a decade of life. If you do have a really old system, you may need to follow our tips for making an old Mac feel like new beyond an OS reinstall.
3. When You’re Selling Your Mac
Because Macs hold their value for so long, you can often resell your machine years after you bought it and make some of the cost back. Whether you plan to sell your Mac online or just give it to a friend, you don’t want the new owner to have access to all your files.
The easiest way to wipe out your own configuration and prepare the Mac for the next person is to reinstall the OS. When you do this, you can erase your storage drive so they can’t access any of your old data.
We’ve looked at how to sell your Mac safely and for the best price, so take a look at that for more information.
4. When You Want to Downgrade macOS
Most of the time, upgrading to the latest version of macOS is a painless experience. Doing so grants access to new features, plus better performance a lot of the time.
But maybe you regret updating the OS on your Mac. Perhaps the latest version made a change that affects your workflow, or maybe it just doesn’t run well on your older machine. In those cases, downgrading macOS is a viable option.
Unfortunately, Apple doesn’t offer an official solution for downgrading macOS. You’ll have to follow our guide to downgrading macOS to use workaround methods for this. There’s no in-place downgrade option, making this another instance where you have to run a fresh install.
How to Reinstall macOS When Needed
Now that we’ve looked at the few cases where reinstalling macOS makes sense, how do you actually perform the reinstall process?
We’ve covered the complete process for reinstalling macOS, so be sure to read that for full details. Here we offer a brief summary of the procedure.
Before You Start the Process
First, make sure you have all your files backed up. You can do this using the built-in Time Machine or another backup solution. While you can reinstall macOS and keep your personal data, backing up is still a smart idea. You may also want to generate a list of installed apps on your Mac so you don’t forget what you had installed.
Next, you should sign out of Apple services like iCloud, iTunes, and iMessage. Some of these only let you use your account on a certain number of devices, so you don’t want a computer that’s no longer around to use a spot.
Reinstalling Through macOS Recovery
When you’re ready to reinstall, shut down your Mac, then reboot while holding Cmd + R. After a few moments, you’ll see the macOS Utilities screen. If you simply want to reinstall macOS without losing any data (to fix issues or get a clean start), select Reinstall macOS from the list.
However, if you want to erase everything on your computer first (such as when selling your machine), you’ll need to enter Disk Utility before reinstalling. Select your disk on the left side of the utility, then use the Erase tab to wipe it clean.
Finally, you can walk through the steps in the Reinstall macOS option. After some time, the reinstall process will complete. You can quit here if you’re selling your system, or continue through the welcome steps to set up your Mac again.
When You Might Need to Replace Your Mac
It’s clear that while you don’t need to reinstall macOS regularly, it can come in handy in certain circumstances. If you fall under any of the above situations, try an OS reinstall if the other troubleshooting steps didn’t fix your problem.
Thankfully, Apple makes it easy to reinstall macOS, so the bulk of the time is just waiting for the process to complete. If reinstalling doesn’t fix your issue, it may be time to replace your Mac.