How to Get Into the MacBook BIOS

A system's BIOS, or Basic Input/Output System, is a software chip in a computer's motherboard that determines how the operating system functions. All Windows operating systems use BIOS, while MacBook computers use an equivalent called EFI, or Extensible Firmware Interface. EFI serves the same purpose as BIOS, where advanced users can configure specific system-level settings. Proceed with caution when accessing this utility, since an error in configuration could jeopardize the stability or functionality on your system.

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BIOS is accessible outside the operating system.

Step

Shut down your MacBook.

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Power down MacBook
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Turn MacBook on
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Step

Power on your MacBook after it has completely turned off.

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Press the "Command-Option-O-F" key combination
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Step

Press "Command," "Option" and the letters "O" and "F" simultaneously before the system starts up.

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Keep keys held
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Step

Hold the keys until a prompt screen launches. You have accessed the MacBook's BIOS equivalent.