How to reinstall macOS without losing data

Back up your data using Time Machine before starting, as it protects against unexpected data loss. 2. Reinstall macOS via Recovery Mode by restarting and holding Command (⌘) R, then selecting Reinstall macOS without erasing your disk to keep all personal files, apps, and settings intact. 3. The process preserves user data like documents, photos, and app preferences, while replacing system files and built-in apps. 4. Avoid using Disk Utility to erase the drive or choosing “Erase All Content and Settings” unless intending a full wipe, and ensure you select Reinstall macOS, not a restore from backup. 5. After reinstalling, your Mac will restart normally with all data preserved, and you should run Software Update to apply the latest patches, ensuring optimal performance and security.

Reinstalling macOS without losing your data is completely possible — in fact, the standard reinstall process is designed to keep your files, apps, and settings intact. Here’s how to do it safely and correctly.

1. Back Up Your Data First (Even If You Don’t Plan To Lose It)

Before doing anything, create a full backup using Time Machine or another reliable method. Even though the reinstall shouldn’t erase your data, hardware issues or power interruptions could cause data loss. Connect an external drive, go to System Settings > General > Time Machine, and follow the prompts to back up.

This step gives you peace of mind and a recovery option if something goes wrong.

2. Use macOS Recovery to Reinstall the OS

The standard macOS reinstall happens through Recovery Mode and does not erase your user data, apps, or settings.

Steps:

• Shut down your Mac.
• Turn it on and immediately hold down Command (⌘) R until you see the Apple logo or a spinning globe.
• Release when you see the macOS Utilities window.

In the Recovery window, choose Reinstall macOS (or Reinstall macOS [Name], like Ventura or Sonoma).

• Click Continue and follow the prompts.
• When asked to choose a disk, select your main drive (usually named “Macintosh HD”) — do not format or erase it.
• The installer will download (if needed) and begin reinstalling the operating system.

This process replaces system files but leaves your personal data untouched.

3. What Gets Deleted (and What Doesn’t)

• ✅ Kept: All your documents, photos, apps, music, user accounts, and preferences.
• ✅ Kept: Files stored in your home folder (Desktop, Documents, Downloads, etc.).
• ❌ Replaced: System files, macOS frameworks, and built-in apps (like Safari, Mail, etc.) are reinstalled fresh.
• ⚠️ Note: If you have apps installed outside the App Store or with custom permissions, they should remain, but it’s wise to check them after reinstall.

You won’t lose data unless you manually erase the drive.

4. Avoid These Mistakes

• Don’t use Disk Utility to erase your drive unless you’re doing a clean install. If you erase the disk, all data will be lost.
• Don’t choose “Erase All Content and Settings” (available on Apple Silicon Macs) unless you want to wipe everything.
• Make sure you’re selecting Reinstall macOS, not Restore From Time Machine Backup unless you actually want to restore from a backup.

5. After Reinstalling

• Your Mac will restart and log you back into your account.
• Everything should look the same — your apps, files, and settings preserved.
• Run Software Update in System Settings to make sure you have the latest patches.
• If any apps misbehave, try reinstalling them individually.

Reinstalling macOS this way is like repairing the engine of a car without touching the interior. It fixes system issues while keeping your personal content safe.

Basically, just avoid formatting the drive and stick to the default reinstall option — your data will stay put.

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