Mac User Guide
- Welcome
- What’s new in macOS Sequoia
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- 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
- Create original images with Image Playground
- Use Apple Intelligence in Photos
- Summarize notifications and reduce interruptions
- Use ChatGPT with Apple Intelligence
- Apple Intelligence and privacy
- Block access to Apple Intelligence features
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- 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
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- 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
- Resources for your Mac
- Resources for your Apple devices
- Copyright
Change Startup Disk settings on Mac
On your Mac, use Startup Disk settings to change your startup disk. You can start up your Mac from a network volume, a different disk, or another operating system. See Change your Mac startup disk.
To change these settings, choose Apple menu 
in the sidebar, then click Startup Disk on the right. (You may need to scroll down.)
Open Startup Disk settings for me
Important: If you have a Mac with an Apple T2 Security Chip, added security features may need to be set in order to change the startup disk. See What is the Startup Security Utility? If you have a Mac with Apple silicon, see Change the security policy.
Option | Description | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Startup Disks | Shows the disks you can use to start your Mac. Click to select the startup disk you want to use. | ||||||||||
Restart | Restart your Mac using the selected startup disk. | ||||||||||
Restart in Target Disk Mode (Mac with Intel chip only) | If you have two Mac computers with USB, USB-C, or Thunderbolt ports, you can connect them so that one of them appears as an external hard disk on the other. This is called target disk mode. See Transfer files between two Mac computers using target disk mode. If you have a Mac with Apple silicon, see Transfer files between a Mac with Apple silicon and another Mac. | ||||||||||
WARNING: When selecting a network startup volume, make sure you select a network startup volume and not a network install image. Selecting a network install image reinstalls your system software and may erase the contents of your disk. A standard network volume icon appears as a globe with a folder. A network install icon appears as a globe with a downward-pointing green arrow.