macOS Sequoia 15

macOS Sonoma 14

macOS Ventura 13

macOS Monterey 12

macOS Big Sur 11.0

macOS Catalina 10.15

macOS Mojave 10.14

macOS High Sierra

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Table of Contents

Welcome
- MacBook Air
- MacBook Pro
- iMac
- Mac mini
- Mac Studio
- Mac Pro
What’s new in macOS Sequoia
- Work on the desktop
- What’s in the menu bar?
- Quickly change settings
- What’s in the Apple menu?
- Search with Spotlight
- Use Siri
- Get notifications
- Open apps from the Dock
- Organize your files in the Finder
- Connect to the internet
- Sign in to your Apple Account
- Set up iCloud
- Browse the web
- Preview a file
- Take a screenshot
- Change your display’s brightness
- Adjust the volume
- Use trackpad and mouse gestures
- Use Touch ID
- Print documents
- Keyboard shortcuts
- Apps on your Mac
- Open apps
- Work with app windows
- Tile app windows
- Use apps in full screen
- Use apps in Split View
- Use Stage Manager
- Get apps from the App Store
- Install and reinstall apps from the App Store
- Install and uninstall other apps
- Create and work with documents
- Open documents
- Mark up files
- Combine files into a PDF
- Organize files on your desktop
- Organize files with folders
- Tag files and folders
- Back up files
- Restore files
- Change System Settings
- Choose your desktop picture
- Add and customize widgets
- Use a screen saver
- Add a user or group
- Add your email and other accounts
- Automate tasks with Shortcuts
- Create Memoji
- Change your login picture
- Change the system language
- Increase the size of what’s on your screen
- How to use Siri
- Customize Siri
- What are Siri Suggestions?
- Use Siri results
- Add Siri Shortcuts
- Get started with Apple Intelligence
- Use Writing Tools
- Use Apple Intelligence in Mail
- Use Apple Intelligence in Messages
- Use Apple Intelligence with Siri
- Get webpage summaries
- Summarize an audio recording
- Use Apple Intelligence in Photos
- Summarize notifications and reduce interruptions
- Apple Intelligence and privacy
- Set up a Focus to stay on task
- Block pop-ups in Safari
- Use Dictation
- Perform quick actions with hot corners
- Send emails
- Send text messages
- Make a FaceTime call
- Edit photos and videos
- Use Live Text to interact with text in a photo
- Start a Quick Note
- Get directions
- Intro to Continuity
- Use AirDrop to send items to nearby devices
- Hand off tasks between devices
- Control your iPhone from your Mac
- Copy and paste between devices
- Stream video and audio with AirPlay
- Make and receive calls and text messages on your Mac
- Use your iPhone internet connection with your Mac
- Share your Wi-Fi password with another device
- Use iPhone as a webcam
- Insert sketches, photos, and scans from iPhone or iPad
- Unlock your Mac with Apple Watch
- Use your iPad as a second display
- Use one keyboard and mouse to control Mac and iPad
- Sync music, books, and more between devices
- Manage Apple Account settings
- Set your Apple Account picture
- What is iCloud?
- What is iCloud+?
- Store files in iCloud Drive
- Share and collaborate on files and folders
- Manage iCloud storage
- Use iCloud Photos
- Get started with Screen Time
- Set up Screen Time for yourself
- Set up Screen Time for a child
- Track app and device usage
- Set time limits for apps and websites
- Set up content and privacy restrictions
- Set up Family Sharing
- Get Family Sharing recommendations
- Add family members to a Family Sharing group
- Remove family members from a Family Sharing group
- Manage sharing and parental settings
- Share a Photo Library
- Collaborate on projects
- Find content shared with you
- Find your family and friends
- Play music
- Watch and listen together with SharePlay
- Listen to podcasts
- Watch TV shows and movies
- Read and listen to books
- Read the news
- Track stocks and the market
- Play games with your friends
- Connect an external display
- Use the built-in camera
- Connect a wireless accessory
- Connect a printer to your Mac
- Connect AirPods to your Mac
- Optimize your Mac battery life
- Optimize storage space
- Burn CDs and DVDs
- Control accessories in your home
- Run Windows on your Mac
- Get started
- Vision
- Hearing
- Mobility
- Speech
- Control what you share
- Set up your Mac to be secure
- Allow apps to see the location of your Mac
- Use Private Browsing
- Keep your data safe
- Understand passwords
- Change weak or compromised passwords
- Keep your Apple Account secure
- Use Mail Privacy Protection
- Use Sign in with Apple for apps and websites
- Find a missing device
- Shut down or restart your Mac
- Start up your Mac in safe mode
- Keep your Mac up to date
- Reinstall macOS
- Erase your Mac
Resources for your Mac
Resources for your Apple devices
Copyright

Determine which disk started up your Mac

Some Mac computers can be started up from a network volume, a different disk, or another operating system.

Important: If you have a Mac with an Apple T2 Security Chip, added security features may be set to prevent the computer from starting up from an external startup disk. See What is the Startup Security Utility? If you have a Mac with Apple silicon, see Change the security policy.

On your Mac, choose Apple menu > System Settings, then click General in the sidebar. (You may need to scroll down.)
Click Startup Disk on the right.
Open Startup Disk settings for me
Your startup disk appears selected.

See alsoChange your Mac startup disk

Helpful?