Restart Mac Choose Startup Disk

You set your Mac or Macbook which disk to start up from when more than one startup disk is connected. This works for USB drives including the NinjaStik

How to Repair a Mac Boot Disk with Disk Utility in Mac OS X. Reboot the Mac and hold down Command+R to boot into Recovery, or hold down OPTION; Select 'Recovery HD' at the boot menu; At the Mac OS X Utilities screen, select 'Disk Utility' Select the boot volume or partition from the left menu and click on the 'Repair' tab; Repair.

And since you only have one disk, this is your startup disk: all 500GB. A Mac with two disks will have the storage divided between them. The Mac drive with the OS on it is the startup disk while the other drive is just used for storage of files. It's possible to have multiple startup disks, but most Macs will only have one. Select the hard disk or partition you want to use as the startup disk. Click Restart to restart your computer and boot from the selected startup disk. To change your startup disk back to the primary disk, repeat the instructions and select the primary disk as the startup disk. Changing Your Mac's Startup Disk at Boot. Reboot your Mac. Hold down 'Option' on your keyboard once you hear the chime sound. Attach your bootable OS X Recovery Disk to your Mac and select it from the prompt list. Your Mac will launch into Recovery Mode and you can start fixing your Mac.

For 2018 to 2020 Macs with the Secure Boot T2 Chip, see the 2020 Macbook Pro Boot from USB instructions.

A 'startup disk' is a volume or partition of a drive that contains a bootable operating system.

You can set your Mac to automatically use a specific startup volume, or you can temporarily override this choice at startup.

1. From the Apple menu choose System Preferences.
2. Click the Startup Disk icon in System Preferences, or choose View > Startup Disk.
3. Select your startup disk from the list of available volumes.

The next time you start up or restart your computer, your Mac starts up using the operating system on the selected volume.

Temporarily change your startup disk with Startup Manager

Startup Manager allows you to pick a volume to start from while the computer is starting up.

Use these steps to choose a startup disk with Startup Manager:

1. Turn on or restart your Mac.
2. Immediately press and hold the Option key. After a few seconds, the Startup Manager appears. If you don't see the volume you want to use, wait a few moments for Startup Manager to finish scanning connected drives.
3. Use your mouse or trackpad, or left and right arrow keys to select the volume you want to use.
4. Double-click or press the Return key to start up your Mac from the volume you selected.

Restart Mac Choose Startup Disk Space Windows

If you have an optical drive connected to your computer, you can insert an installation disc to see it in Startup Manager. You can also attach FireWire or USB external hard drives that contain an operating system to add to the list of startup volumes.

Startup Manager automatically adds bootable volumes as you connect them.

Restart in OS X from Boot Camp

Restart Mac Choose Startup Disk Mac

If you have started up your Mac in Windows using Boot Camp, you can use the Boot Camp system tray to switch your startup disk default back to OS X.

1. In Windows, click the Boot Camp icon in the system tray.
2. From the menu that appears, choose Restart in OS X.

Start from OS X Recovery

You can also start your Mac from OS X Recovery or Internet Recovery if your Mac was manufactured after 2011.

For 2018 to 2020 Macs with the Secure Boot T2 Chip, see the 2020 Macbook Pro Boot from USB instructions.

A 'startup disk' is a volume or partition of a drive that contains a bootable operating system.

You can set your Mac to automatically use a specific startup volume, or you can temporarily override this choice at startup.

1. From the Apple menu choose System Preferences.
2. Click the Startup Disk icon in System Preferences, or choose View > Startup Disk.
3. Select your startup disk from the list of available volumes.

The next time you start up or restart your computer, your Mac starts up using the operating system on the selected volume.

Temporarily change your startup disk with Startup Manager

Startup Manager allows you to pick a volume to start from while the computer is starting up.

Use these steps to choose a startup disk with Startup Manager:

1. Turn on or restart your Mac.
2. Immediately press and hold the Option key. After a few seconds, the Startup Manager appears. If you don't see the volume you want to use, wait a few moments for Startup Manager to finish scanning connected drives.
3. Use your mouse or trackpad, or left and right arrow keys to select the volume you want to use.
4. Double-click or press the Return key to start up your Mac from the volume you selected.

Restart Mac Choose Startup Disk Space Windows

If you have an optical drive connected to your computer, you can insert an installation disc to see it in Startup Manager. You can also attach FireWire or USB external hard drives that contain an operating system to add to the list of startup volumes.

Startup Manager automatically adds bootable volumes as you connect them.

Restart in OS X from Boot Camp

Restart Mac Choose Startup Disk Mac

If you have started up your Mac in Windows using Boot Camp, you can use the Boot Camp system tray to switch your startup disk default back to OS X.

1. In Windows, click the Boot Camp icon in the system tray.
2. From the menu that appears, choose Restart in OS X.

Start from OS X Recovery

You can also start your Mac from OS X Recovery or Internet Recovery if your Mac was manufactured after 2011.

To start your Mac from the Recovery System, use these steps:

1. Start up or restart your computer.
2. Hold down the Command and R keys on your keyboard until you see the Apple logo appear onscreen.

If you don't see a volume listed

If you don't see the volume you want to start your computer from, check the following:

• If you're using an external drive, make sure it's connected and turned on.
• Make sure you've installed an operating system, like OS X or Windows on the drive you're trying to start from. Volumes that don't contain a valid operating system aren't listed in Startup Disk or Startup Manager.
• If you've installed an operating system on a drive but it isn't listed, the volume you're trying to start from might need repair. If the volume contains OS X, start your computer from OS X Recovery and use Disk Utility to repair the volume, or reinstall OS X on the volume using the Recovery System.
• Depending on the Mac you are using and the version of OS X that is installed, the Recovery System volume (Recovery HD) might not show up in Startup Manager. Press Command-R during startup to start your Mac from the Recovery System.

For 2018 / 2019 Macbook Pro with the Secure Boot T2 Chip, see the 2018 Macbook Pro Boot from USB instructions.