Does Reinstall Mac Os Wipe Hard Drive


Important: To reinstall macOS, you must be connected to the Internet.In the menu bar, choose Apple menu Restart. Select Disk Utility, then click Continue.Select your startup disk on the left, then click Erase.Click the Format pop-up menu, choose Mac OS Extended, enter a name, then click Erase. If you sell your Mac or just want a fresh start, you can erase the drive and reinstall OS X. Here's how to do it with a Mac Mini running Mountain Lion.

With macOS Catalina officially released, more and more people jump on the bandwagon to try its expanded features, such as screen extension with an iPad or the new Apple Podcasts app. And why not?

The problem is that it might not always work as intended. Glitches in macOS Catalina are commonplace — even fully released operating systems like Mojave or High Sierra could freeze and crash from time to time. No software is immune.

But what do you do if this case? The surefire way to deal with jaded performance is to reinstall mac OS Catalina altogether. Read through our guide below to learn how.

How To Reinstall Mac OS Catalina

It’s important to note that when you reinstall macOS Catalina the process simply updates the operating system and doesn’t affect any files on your hard drive or user files or even settings. That makes reinstalling principally different from performing a clean install, which erases everything.

Simple mail app fior seniors on a mac account. Here are the proper steps to follow to reinstall mac OS Catalina.

1. Back up your Mac first

By default, the best thing you could do before making any significant changes to how your Mac works is to back it up. Backups are just like saves before encountering challenges in video games — represent the point you can always come back to.

There are lots of great backup solutions on the market to suit every need. If you don’t have the time to search for something specific, your Mac features a decent native option — Time Machine.

To get Time Machine started:

  1. Connect an external USB or WiFi hard drive to your Mac
  2. Go System Preferences ➙ Time Machine
  3. Click on Select Backup Disk…
  4. Press Use Disk

2. Delete junk off your Mac to speed it up

There’s nothing better than the feeling of a brand new Mac with a brand new macOS. If only the latter is new, the experience could be subpar. Trying to get the most out of macOS Catalina on your older machine might be a challenge. But don’t hurry to your local Apple Store just yet — not all is lost.

Just like the dust behind your couch or on the top of your kitchen cupboards, small bits of system files, caches, and hidden libraries tend to aggregate over the years and never get deleted, eventually slowing down everyday processes. While it’s possible to clear out some of them manually, others require specific technical knowledge and lots of time.

Luckily, there’s a professional automatic solution available — CleanMyMac X. Optimizing behind-the-curtain processes on your Mac with CleanMyMac X is no more difficult than clicking a single button:

  1. Download a free trial of CleanMyMac X
  2. Open the app and navigate to System Junk in the left-side panel
  3. Click Scan and wait for the process to complete
  4. When done, press Review Details
  5. Uncheck anything you’d like to keep and click Clean

Now your Mac is free of all the pointless log files, user caches, language files, old updates, and more. Which directly translates into improved processing power, memory usage, and response time. At last, your Mac is ready to take full advantage of macOS Catalina.

3. Reinstall macOS Catalina in Recovery Mode

With your Mac in top shape, it’s time to get that macOS Catalina download link. Surprisingly, you won’t find it in Software Update or even App Store (where it used to be in macOS High Sierra).

The correct way to reinstall macOS Catalina is to use your Mac’s Recovery Mode:

  1. Restart your Mac and then hold down ⌘ + R to activate Recovery Mode
  2. In the first window, select Reinstall macOS ➙ Continue
  3. Agree to the Terms & Conditions
  4. Select the hard drive you’d like to reinstall mac OS Catalina to and click Install

The reinstallation process will start shortly and roughly take 30 minutes. When complete, your Mac will start up as usual. No files should be lost, but it’s always a good idea to check CleanMyMac X’s Applications Updater to see if you can improve compatibility of the new macOS with any of your existing apps:

  1. Launch CleanMyMac X
  2. In the left-side panel, navigate to Updater
  3. View any available updates and their notes and click on Update

Finally, in case you notice any files or apps missing, or settings misconfigured, you could open up Time Machine to restore a specific folder or the whole backup from the step one:

  1. Launch Time Machine from Applications
  2. Simply scroll all backup versions to find the file you’re looking for
  3. Click Restore

If you decide to restore the whole backup, make sure to then repeat the whole process to optimize your Mac and reinstall macOS Catalina as detailed above. The good thing is that more often than not the reinstallation works wonders right from the first time.

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macOS Recovery can help you easily reinstall the Mac operating system on your built-in drive or an external drive. This blog answers 'Does reinstalling macOS delete files?' Besides, it also suggests using EaseUS Data Recovery Wizard for Mac to recover lost and deleted files in the easiest and safest way.


This page illustrates the detailed process of recovering data from a failed Mac computer before you reinstalling the macOS. If you are having the same issue, follow through this page to see how to get data out of the failed Mac computer before macOS reinstallation:

Workable SolutionsStep-by-step Troubleshooting
Phrase 1. Create Bootable USBRun EaseUS Mac data recovery software on another Mac computer > Create bootable USB..Full steps
Phrase 2. Recover Mac DataConnect bootable USB to failed Mac > Boot computer from USB > recover data..Full steps

'My macOS Catalina got corrupted, and the login screen doesn't appear. If I reinstall macOS from recovery menu will my previously installed software and data be deleted? And if so how can I back them up on a hard drive, the data and the software are very important to me.'

Reinstalling macOS of macOS Recovery can help you replace the current problematic OS with a clean version quickly and easily. Technically speaking, simple reinstalling macOS won't erase your disk either delete files. You probably don't need to erase, unless you're selling or giving away your Mac or having an issue that requires you to wipe. Besides, If you suspect there's something wrong with your startup drive, you can use the Disk Utility to scan and repair them from the recovery screen, which might be a quicker and more convenient alternative than erasing and reinstalling your macOS.

How to Recover Data When Mac Needs to Be Erased and Reinstall macOS

If you're encountering the same issue as said at the beginning of the article, that your computer gets corrupted, and you have to consider a complete restart in Recovery Mode. At this time, you need to use the Disk Utility in macOS Recovery to erase your Mac hard drive first, and go on to reinstall the macOS.

As well all know, erasing the hard disk on Mac will inevitably cause data loss and make the files unrecoverable. How to recover data in the easiest way when Mac failed to start? Don't worry, here comes the EaseUS Mac data recovery software, which enables you to create a bootable USB drive on another Mac that works well, then, restart your Mac from it, and go ahead to recover files. Especially to restore data on system drive under macOS 10.13, it's very safe to recover from bootable media. Useful for any emergency, no secondary data damage!

Now, follow the step-by-step guides below to see how to recover data from Mac that fail to start and need to erase and reinstall OS. The whole tutorials will be divided into two parts: how to create a USB bootable media and how to recover data from bootable media.

How to Create a USB Bootable Media

Step 1. Install and run EaseUS Data Recovery Wizard for Mac on another Mac computer, select 'File' > 'Create Bootable USB'. Then, choose a USB drive to create the bootable disc.

Does Reinstall Mac Os Wipe Hard Drive

The creator will prompt to erase the drive to reallocate the space, then it can write the bootable files to this drive. Please back up all USB files with EaseUS Todo Backup for Mac before processing 'Eraser'.

Step 2. The program starts to create a 2GB space and save the boot files. The rest space on the USB can be still used for storage.

Step 3. Once it completes, please follow the guide to boot the corrupted Mac from the bootable disc and start the recovery. We suggest you restore the data to an external hard drive.

How to Recover Data from Mac Hard Disk

Step 1. Select the disk location (it can be an internal HDD/SSD or a removable storage device) where you lost data and files. Click the Scan button.

Does Reinstall Mac Os Wipe Hard Drive Mac

Step 2. EaseUS Data Recovery Wizard for Mac will immediately scan your selected disk volume and display the scanning results on the left pane.

Reinstall Mac Os X From Usb

Step 3. In the scan results, select the file(s) and click Recover Now button to have them back.

After the data recovery, you can use the 'Disk Utility' to erase your Mac disk, and then choose 'Reinstall macOS' to finish the reinstalling.

Os X Wipe And Reinstall

See More about EaseUS Data Recovery Wizard for Mac

EaseUS Mac data recovery program allows you to recover deleted files from the emptied trash bin, internal/external hard drive, SSD, corrupted or formatted memory card, including memory sticks, SD cards, CF cards, XD & MMC cards. Besides, it also enables you to recover lost Word, Excel, PPT, etc.

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