To use any of these key combinations, press and hold the keys immediately after pressing the power button to turn on your Mac, or after your Mac begins to restart. Keep holding until the described behavior occurs.

1. Option Key On Keyboard For Mac Keyboard
2. Option Key On Microsoft Keyboard For Mac

• Command (⌘)-R: Start up from the built-in macOS Recovery system. Or use Option-Command-R or Shift-Option-Command-R to start up from macOS Recovery over the Internet. macOS Recovery installs different versions of macOS, depending on the key combination you use while starting up. If your Mac is using a firmware password, you're prompted to enter the password.
  
• Option (⌥) or Alt: Start up to Startup Manager, which allows you to choose other available startup disks or volumes. If your Mac is using a firmware password, you're prompted to enter the password.
  
• Option-Command-P-R:Reset NVRAM or PRAM. If your Mac is using a firmware password, it ignores this key combination or starts up from macOS Recovery.
• Shift (⇧): Start up in safe mode. Disabled when using a firmware password.
• D: Start up to the Apple Diagnostics utility. Or use Option-Dto start up to this utility over the Internet. Disabled when using a firmware password.
• N: Start up from a NetBoot server, if your Mac supports network startup volumes. To use the default boot image on the server, hold down Option-N instead. Disabled when using a firmware password.
• Command-S: Start up in single-user mode. Disabled in macOS Mojave or later, or when using a firmware password.
• T: Start up in target disk mode. Disabled when using a firmware password.
• Command-V: Start up in verbose mode. Disabled when using a firmware password.
• Eject (⏏) or F12 or mouse button or trackpad button: Eject removable media, such as an optical disc. Disabled when using a firmware password.

Option Key On Keyboard For Mac Keyboard

If a key combination doesn't work

If a key combination doesn't work at startup, one of these these solutions might help:

• Be sure to press and hold all keys in the combination together, not one at a time.
• Shut down your Mac. Then press the power button to turn on your Mac. Then press and hold the keys as your Mac starts up.
• Wait a few seconds before pressing the keys, to give your Mac more time to recognize the keyboard as it starts up. Some keyboards have a light that flashes briefly at startup, indicating that the keyboard is recognized and ready for use.
• If you're using a wireless keyboard, plug it into your Mac, if possible. Or use your built-in keyboard or a wired keyboard. If you're using a keyboard made for a PC, such as a keyboard with a Windows logo, try a keyboard made for Mac.
• 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.

If for any reason you are using a PC keyboard with Mac OS X you may need to use some abbreviations that require the Option button. But in the previous lines of this guide, I specified that the Option key coincides with Alt, so if you use a Windows keyboard just press the Alt button to signal the option to OSX. Likewise, the Windows / Microsoft button coincides with Command while there are no. . Under the Keyboard Tab look for the Modifier Keys. On the Select Keyboard dropdown choose K750. Click the dropdown next to OPTION Key and select Command. Click the dropdown next to COMMAND Key and select Option. The WINDOWS key becomes the ALT / OPTION key on Mac OS and the ALT key becomes the COMMAND key on Mac OS.

Remember that some key combinations are disabled when your Mac is using a firmware password.

Learn more

Option Key On Microsoft Keyboard For Mac

• Learn what to do if your Mac doesn't turn on.
• Learn about Mac keyboard shortcuts that you can use after your Mac has started up.