Boot Keys For Macbook Pro
Boot Keys For Mac Computer

When the proverbial manure hits the fan and prevents your Mac from booting as you want, knowing the right startup key combination can save the day, whether you boot into Safe Mode, Recovery, Apple Diagnostics, or from another disk entirely.

Here are fifteen startup key combinations that can save the day when things go wrong. Not all are useful on today’s Macs, but we wanted the list to be complete.

Option: Invoke Startup Manager — The first startup key every Mac user should know is the Option key. Press and hold Option as your Mac boots to enter the Startup Manager, which lets you select which disk to boot from.

Startup Manager is primarily useful for booting from an alternative drive, like a system clone, USB thumb drive, or a Boot Camp partition. However, you can also use it to force a boot from your primary drive if your Mac is stubbornly booting from another disk. Startup Manager may also help identify a flaky hard drive; if the drive you’re looking for doesn’t appear in Startup Manager, you know you have a problem.

. The C key forces the Mac to start up from a bootable CD-ROM, if one is present, which is useful if something goes wrong with your startup hard disk. This key doesn't work with some older Macs or clones that didn't use Apple CD-ROM drives; they require Command- Shift-Option-Delete instead (see below). Option activates the new Startup Manager.

Mac startup key combinations To boot your Intel-based Mac into any of the macOS built-in startup modes, you must press and hold one or more keys detailed below after turning on the computer. Press the keys immediately after hearing the startup sound, unless otherwise specified. Manually restart: Power (⎋). If you’re using a Mac notebook computer with an external keyboard, make sure you press and hold the Option key on the built-in keyboard. Restart using Boot Camp Control Panel: Click in the right side of the taskbar, click the Boot Camp icon, then choose Restart in macOS. This also sets the default operating system to macOS. Boot your Mac holding COMMAND + R keys until you see the following screen below. If your Mac does not display the above screen, your Mac likely does not have the built in recovery option. Try to force booting into recovery mode below. What are all the Startup key combinations for Power Mac? These combinations work with Intel-based Mac computers. That is not the answer we want, we are asking about Power Macs (PowerPC Based Macintosh.) This question was asked before in the v10.7 Lion (Intel) community, and hopefully we may have better luck posting here in the Power Mac community.

If you have a bootable external drive, booting from that drive can also help you isolate problems or provide a different environment, such as a different version of OS X.

T: Target Disk Mode — What if you want to boot from another Mac’s drive using Startup Manager? You can connect the Macs via FireWire or Thunderbolt, and then put the other Mac into Target Disk Mode, which lets it serve as an external drive. Hold T during boot to enter this mode. If either Mac lacks a FireWire or Thunderbolt port, you’re out of luck.

In addition to troubleshooting, Target Disk Mode can also be useful for quickly transferring many gigabytes of files. And if your main Mac’s display fails, you can use Target Disk Mode to turn it into the boot drive for another Mac with a working screen.

Shift-Control-Option: Reset the SMC — When your Mac is exhibiting truly odd behavior, it may be worth resetting the System Management Controller (SMC), which controls all manner of things, such as batteries, keyboard backlight, and cooling fans. Apple lists all the things an SMC reset can fix.

On desktop Macs, you reset the SMC by unplugging the power cable for 15 seconds, plugging it back in, and turning the Mac on after 5 seconds. On older Mac notebooks, you can reset the SMC by removing the battery and power adapter, holding down the power button for 5 seconds to drain the capacitors, reinserting the battery, and turning it back on again.

However, for newer Mac notebooks, where it’s impossible to remove the battery, you need to know this key combo: Shift-Control-Option, using the keys on the left side of the keyboard. Shut down your Mac, connect it to power, press Shift-Control-Option, and then press the power button while holding those keys down. Release the keys and press the power button again to fire up the Mac with a fresh set of SMC settings.

Command-Option-P-R: Reset NVRAM — The other quick fix is resetting Non-Volatile Random Access Memory (NVRAM), which you do by holding Command-Option-P-R during startup. The Mac startup chime should sound a second time. After that, release the keys. (The reason for using P and R in the key combination is that Apple used to call this bit of non-volatile memory “PRAM,” for Parameter RAM.)

NVRAM controls things like speaker volume, screen resolution, and startup drive selection. Like an SMC reset, an NVRAM reset can fix a host of seemingly random issues.

Shift: Safe Mode — If your Mac gets stuck during the boot process, booting in Safe Mode might help you diagnose what’s wrong. To invoke Safe Mode, hold the Shift key while booting. It does a few things:

Verifies and repairs your startup disk
Loads only essential kernel extensions
Ignores startup and login items
Disables user-installed fonts
Deletes all system cache files

Simply booting in Safe Mode may solve your problem, if it was related to directory corruption or a messed-up cache file. If a Safe Mode boot works fine, try a regular boot immediately, and if it proceeds normally, you’re all set.

However, if your Mac boots fine in Safe Mode, but has problems otherwise, you probably have a software problem related to something that loads at startup. You might guess that a third-party kernel extension was the culprit, but it could also be a corrupt font. Start poking around in the various Library folders on your Mac.

(If all you want to do is disable login items, press Shift when you click the Log In button in the login window, or as soon as you see the progress bar in the startup screen. Release it when you see the Desktop or Dock.)

Command-R: Recovery — Every modern Mac can boot into a special mode called Recovery, which provides tools to resolve a variety of problems. The system disk of most Macs contains a small partition containing a stripped-down version of OS X, which you can boot from by holding Command-R as your Mac boots. If the recovery partition is missing for some reason, you can load the Recovery software from the Internet by holding Command-Option-R at startup. Needless to say, loading Internet Recovery takes quite a bit longer; happily, it does provide a time estimate.

Recovery gives you seven options:

Restore from a Time Machine Backup: You do have a Time Machine backup, right? Right?
Reinstall OS X: You don’t have to wipe your disk and start from scratch; this option reinstalls the currently installed version of OS X over your existing install, which can fix missing or corrupted system files. If you use Internet Recovery, you get the version of OS X that originally came with your Mac instead.
Get Help Online: This option opens Safari so you can browse Apple’s support site for help.
Disk Utility: Clicking this item in the list brings up the Disk Utility app, which can check and repair your disks. If absolutely necessary, you can use Disk Utility to erase your system disk, onto which you can then restore your data from Time Machine. (You do have that backup, right?)
Firmware Password Utility: Choose Utilities > Firmware Password Utility to launch this app, which lets you set and turn off a firmware password. You might want to enable a firmware password to make Find My Mac more secure (see “Disable Find My Mac by Resetting NVRAM,” 22 July 2016).
Network Utility: Also available from the Utilities menu, Network Utility lets you test local and Internet connectivity using tools like Netstat, Ping, Traceroute, and more. It’s more easily used when the Mac isn’t in Recovery mode, but it’s here if you need it.
Terminal: For those who are more comfortable at the command line, you can also launch Terminal from the Utilities menu

Boot Keys For Mac