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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 web page summaries
- Summarise an audio recording
- Create original images with Image Playground
- Use Apple Intelligence in Photos
- Summarise 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
If you can’t install macOS on an external disk
You can install macOS only on disks with the GUID Partition Table scheme. Use Disk Utility to check your external disk’s partition scheme to make sure it’s the required scheme.
Go to the Disk Utility app
on your Mac.Choose View > Show All Devices (a tick indicates it’s selected).
Select the external disk in the list on the left.
Disks appear flush left in the list (volumes are indented below disks).
On the right, check whether the description below the disk name mentions GUID Partition Map.
If it doesn’t, you need to reformat the external disk before you can install macOS on it. For information about reformatting an external disk using Disk Utility on Mac, see Erase and reformat a storage device.
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