If you're using Boot Camp to start up from Microsoft Windows, set Startup Disk preferences to start up from macOS instead. Then shut down or restart and try again.

Some key combinations don't work when your Mac is using a firmware password.

If you're using a keyboard made for a PC, such as a keyboard with a Windows logo, try a keyboard made for Mac. Or use your built-in keyboard or a wired keyboard.

If you're using a wireless keyboard, plug it into your Mac, if possible.

Some keyboards have a light that flashes briefly at startup, indicating that the keyboard is recognized and ready for use.

You might need to wait a few seconds before pressing the keys, to give your Mac more time to recognize the keyboard as it starts up.

Then press and hold the key combination after pressing the power button to turn on your Mac. If you can't shut down, press and hold the power button for up to 10 seconds, until your Mac turns off.

If you can't get a key combination to work when restarting your Mac, shut down your Mac first.

Press and hold all keys in the combination together, not one at a time.

To do this, you can boot into Recovery mode (as described above) and select 'Reinstall macOS' from the options available. Reinstall your operating system: If all else fails, you may need to reinstall your operating system. From here, you can try repairing your startup disk using Disk Utility. As soon as you hear the startup sound, press and hold down the Command + Option + P + R keys together until you hear the startup sound again.Ĭheck your connections: Make sure that all cables, including the power cable, are securely connected to your MacBook Pro.īoot into Recovery mode: Press and hold down the Command + R keys while your MacBook Pro is booting up.

Reset your NVRAM or PRAM: Shut down your MacBook Pro and then press the power button to turn it on. Make sure that your startup disk is selected as the default disk. Here are some steps you can try to resolve this issue:Ĭheck your startup disk: Go to the Apple menu and select 'Startup Disk'. Also see Freeing space on your Mac OS X startup disk. Visit The XLab FAQs and read the FAQ on freeing up space on your hard drive.

You can remove data from your Home folder except for the /Home/Library/ folder. As no further input was gathered against my last clarifying question, I now provide a general answer based on the given description and common situations.Generally speaking, if you are seeing a question mark icon when you try to boot up your MacBook Pro Retina 2015, it indicates that your computer is not able to find a bootable operating system. See Lion/Mountain Lion/Mavericks' Storage Display.

How to clear startup disk on mac