How to install the operating system I have a question mark

Choose System Preferences from the Apple menu (), then click Startup Disk.

Click the icon of the disk you normally use to start up your computer. It's usually named Macintosh HD.

Close the System Preferences window.

Your Mac should now start up without the flashing question mark.

If your Mac starts up with a flashing question mark, but then doesn't continue starting up, try these steps.

Turn off your Mac by pressing and holding the power button for a few seconds.

Press the power button once to turn your Mac back on. Immediately press and hold the Command and R keys on your keyboard to start your Mac from macOS Recovery. Keep these two keys held down until you see an Apple logo or globe.

If prompted, select a Wi-Fi network to connect to the Internet as part of a startup.

After the macOS utility window appears, choose Startup Disk from the Apple menu.

Select your startup disk, then click Restart.

If you don't see your startup disk in the Startup Disk window, close the window and try the next sections of this article.

If you don't see your startup disk

If you don't see your startup disk in the Startup Disk window, use these steps to see if your startup disk needs directory repair.

Open Disk Utility from the macOS utility window.

In the Disk Utility window, select your startup disk (usually named "Macintosh HD") from the left side of the window.

Click the First Aid tab.

Click the Repair Disk button to verify and repair any issues with your startup disk.

After your disk is successfully repaired, quit Disk Utility.

Choose Startup Disk from the Apple menu. Select your startup disk, then click Restart. If you still don't see your Startup Disk, try reinstalling macOS on your startup disk.

If you don't see your built-in startup disk in the Disk Utility window, or if Disk Utility indicates there's a hardware issue, your Mac might need repair. Make an appointment with an Apple Genius or an Apple Authorized Service Provider for more help.