What is Option D on Mac?

D: Start up to the Apple Diagnostics utility. Or use Option-D to start up to this utility over the Internet. Disabled when using a firmware password.

What does holding D while booting Mac?

Start up your machine while holding down the Shift key to have OS X only load required kernel extensions and login items. It will disable all non system fonts, all startup items, and login items. This Safe Mode feature is a great way to troubleshoot OS X applications and extensions that aren’t working properly.

How do I start my Mac in Boot mode?

Press the Power button to turn on your Mac (or Restart your Mac if it’s already on). When you hear the startup chime, press and hold the Option key. Holding that key gives you access to OS X’s Startup Manager. Once the Startup Manager screen appears, release the Option key.

How do I change the boot options on a Mac?

Change your startup disk for every startup

1. On your Mac, choose Apple menu > System Preferences, then click Startup Disk. Open Startup Disk preferences for me. If the lock at the bottom left is locked , click it to unlock the preference pane.
2. Click the icon of the disk you want to use, then click Restart.

How do I recover my Mac?

How to start Mac in Recovery Mode

1. Click on Apple logo at the top left of the screen.
2. Select Restart.
3. Immediately hold down the Command and R keys until you see an Apple logo or spinning globe.
4. Eventually your Mac will show the Recovery Mode Utilities window with the following options:

How do I force my Mac into recovery mode?

If you can’t start up in macOS Recovery, you could try forcing it to boot in macOS Recovery over the Internet. Here’s how to do that: Hold down Option/Alt-Command-R or Shift-Option/Alt-Command-R at startup to force macOS Recovery to boot over the Internet.

How do you know if your Mac is in safe mode?

How do you know you are in Safe Mode

1. Click on the Apple logo in the menu (top left).
2. Click in About This Mac.
3. Click on System Report.
4. Click on Software and check what the Boot Mode is listed as – it will say Safe if you are in Safe Mode, otherwise it will say Normal.

How do I safe boot my Mac?

Start up your Mac in safe mode

1. On your Mac, choose Apple menu > Shut Down. After your Mac shuts down, wait 10 seconds.
2. Restart your Mac, then immediately press and hold the Shift key.
3. Release the Shift key when you see the login window.

How do I get into the BIOS on an iMac?

How to Open the iMac BIOS

1. Turn on your iMac by pressing the power button.
2. Open OpenFirmware by holding down the “Command,” “Option,” “O” and “F” keys simultaneously. Listen for Two chimes will sound and wait for the next command.
3. Tip.

How do I boot a Mac from a USB drive?

Press and hold the “Option” key when you hear the startup sounds—this will bring you to the Startup Manager. Once the Startup Manager appears, you can release the Option key. Startup Manager will then start scanning your device for drives it can boot from, including your USB.

How do I boot a Mac in Safe Mode?

How do I fix a Mac startup problem?

On a Mac laptop:

1. Shut down the MacBook.
2. Unplug and then reconnect the power cable.
3. Press Shift + Ctrl + Option/Alt keys and the power button at the same time.
4. Now release all those keys and the power button at the same time.
5. You may see the light on the power cable flicker.
6. Restart your MacBook.

What is the keyboard shortcut to reboot a Mac?

One of the most common keyboard shortcuts is CTRL + ALT +DEL. This combination was originally used by IBM to reset or reboot the computer. Under Mac OS X, this key combination has no special meaning, since a reset is triggered by the Cmd+Ctrl+Switch On key or by a special reset key.

How do you boot up a Mac?

Boot up the Mac or restart the computer. As soon as the boot process begins, hold down COMMAND + S keys together. Keep holding the Command and S keys until you see white text on a black background, indicating that single user mode is loading.

What is the command key for Mac OS?

The Apple key, also known as the Command key, is labelled with Cmd and the quadruple loop symbol: The Apple key is used with a single letter key for many of the Mac’s most common actions: Apple-S saves in most common applications, for instance, and Apple-P prints. Apple-T opens a new tab in your web browser.

What is boot option key?

Just as its name implies, Boot Menu Key is the keypad to access Boot Menu option. Windows users usually access boot menu by pressing keyboard boot menu key in the keyboard when their personal computer is booting up. Note: Common boot menu keys to access the boot menu are F2, F10, F12, Delete, Esc, etc.