Getting into BIOS on Windows and Mac

To enter BIOS setup, you restart your computer and press a specific key during the boot process — before Windows or macOS loads. The key varies by manufacturer: on most Dell, HP, and Lenovo machines it's F2 or Delete; on Asus it's usually Delete or F2; on Apple computers running Intel chips, hold Command + Option + P + R during startup to access firmware settings. You have only a few seconds after power-on to catch the window, so you need to press the key repeatedly as soon as you see the manufacturer's logo.

If you miss the window, the computer will boot normally into your operating system. Restart and try again — there's no penalty for missing it. Some newer computers, especially those with fast solid-state drives, boot so quickly that the key-press window is only one or two seconds long. If you're having trouble, try pressing the key immediately after pressing the power button, and keep pressing it until you see the BIOS screen or the operating system loads.

On newer Windows machines with UEFI firmware (most computers made after 2012), you can also enter BIOS from within Windows itself. Go to Settings > System > Recovery, click Restart now under "Advanced startup", then select Troubleshoot > Advanced options > UEFI Firmware Settings. This method is slower but more reliable if you keep missing the boot-time window.

Key Takeaways

  • Press Delete, F2, or F12 repeatedly during startup, right after you see the manufacturer's logo, to enter BIOS before your operating system loads.
  • The exact key depends on your computer's brand — check your manufacturer's website or the startup screen itself, which often displays the correct key.
  • On Windows machines with UEFI firmware, you can enter BIOS from Settings > System > Recovery > Advanced startup instead of restarting.
  • BIOS changes take effect immediately and can prevent your computer from starting, so only change settings if you know what they do.

Finding the Right Key for Your Computer Brand

The key you need depends on who made your computer. Most manufacturers display the correct key on the startup screen itself — look for text that says "Press [key] to enter Setup" or "Press [key] for BIOS" during the first few seconds after power-on. If you can't read it in time, you can look up your specific model on the manufacturer's support website.

Common keys by brand: Dell uses F2 (or Delete on older models), HP uses F10 (or Esc then F10), Lenovo uses F2 (or Enter then F1), Asus uses Delete (or F2), Acer uses Delete (or F2), and MSI uses Delete. If you built your own computer, the key depends on your motherboard manufacturer — check the manual or the motherboard maker's website. On Apple computers, the process is different: restart and hold Command + Option + P + R for Intel Macs, or restart and hold the power button for 10 seconds on Apple Silicon Macs (M1, M2, M3).

If you're not sure which key to press, restarting and trying F2 or Delete works on about 80% of computers. If neither works, restart again and watch the startup screen more carefully for the prompt, or search "[your computer model] enter BIOS" online.

What Happens When You Enter BIOS

Once you're in BIOS, you'll see a menu with options organized by category — usually something like "Main", "Advanced", "Security", "Boot", and "Exit". The exact layout and options vary widely by manufacturer and model. You navigate using arrow keys, Enter to select, and Escape or a specific key (usually F10 or Esc) to save and exit.

The BIOS interface is text-based and looks nothing like Windows or macOS. It runs before your operating system loads, so it doesn't use your mouse or the graphical interface you're used to. Some newer computers have a graphical BIOS with a mouse, but most still use keyboard navigation only. Take your time — you're not on a timer, and nothing happens until you explicitly save changes.

Common sections you'll see: Main shows your hardware (processor, RAM, storage), Boot controls which device your computer starts from, Security manages passwords and secure boot settings, and Advanced contains technical options most users never need to touch. If you're not sure what a setting does, don't change it — leave it at the default value.

Saving and Exiting BIOS Without Making Changes

If you entered BIOS to look around but didn't change anything, you can exit safely by pressing the key shown at the bottom of the screen — usually F10 or Esc — and selecting "Exit Without Saving" or "Discard Changes". Your computer will restart normally and boot into Windows or macOS as usual.

If you did make changes and want to keep them, select "Save and Exit" or press F10 and confirm. The computer will restart and apply the new settings. If you made a change that prevents your computer from starting, you'll need to restart again, enter BIOS, and change the setting back — or reset BIOS to factory defaults (usually an option in the Exit menu).

Never turn off your computer while you're in BIOS or while it's saving changes. If the power goes out during a BIOS update or save, your computer may not start again. If you have a laptop, make sure it's plugged in before entering BIOS, especially if you're planning to make changes.

Common Reasons to Enter BIOS

Most people enter BIOS to change the boot order — the sequence in which the computer checks for an operating system. This is necessary if you're installing Windows or another operating system from a USB drive, or if you want to boot from an external hard drive. You'll go to the Boot menu and move the USB drive or external device to the top of the list.

Other common reasons include enabling or disabling hardware features (like integrated graphics or USB ports), checking how much RAM your computer has, resetting a forgotten BIOS password, or updating the BIOS itself. Some security settings also live in BIOS — for example, enabling Secure Boot (which checks that Windows hasn't been tampered with) or disabling legacy USB support if you're having trouble with older devices.

If you're troubleshooting a hardware problem, a technician might ask you to check a specific BIOS setting or reset BIOS to defaults. In that case, they'll tell you exactly which menu to navigate to and what to change. Don't change BIOS settings based on advice from the internet unless you understand what the setting does and why you're changing it.

Resetting BIOS to Factory Defaults

If you changed a BIOS setting and your computer won't start, or if you forgot a BIOS password, you can reset BIOS to its original factory settings. Most computers have a "Reset to Defaults" or "Load Setup Defaults" option in the Exit menu — navigate there, select it, confirm, and the computer will restart with all settings restored.

If you can't enter BIOS at all (for example, because you set a BIOS password and forgot it), you may need to clear the CMOS battery. This is a small coin-shaped battery on the motherboard that stores BIOS settings. Turning off the computer, unplugging it, opening the case, removing the battery for 10 seconds, and reinserting it will reset BIOS to defaults. This is more involved and requires opening your computer — if you're not comfortable doing this, a technician can do it for you.

Resetting BIOS is safe and won't affect your files or operating system. Your computer will boot normally after the reset, and you can reconfigure any settings you need.

Frequently Asked Questions

What if I press the key but nothing happens?

You may have pressed the wrong key, or you pressed it too late. Restart the computer and try again, pressing the key immediately after you see the manufacturer's logo. If you're on a laptop, try holding the key down instead of tapping it. If nothing works after several tries, search your computer model plus "enter BIOS" to confirm the correct key.

Can I use the mouse in BIOS?

Most BIOS menus are keyboard-only, but some newer computers have a graphical BIOS that supports the mouse. If the mouse doesn't work, use the arrow keys to navigate and Enter to select. The Escape key usually goes back to the previous menu.

Will entering BIOS delete my files?

No. Just looking at BIOS settings or navigating the menus won't affect your files. Only if you change a setting and save it could something go wrong — and even then, your files stay on your hard drive. Changing BIOS settings can affect how your computer starts or what hardware it recognizes, but not the data stored on it.

What if I accidentally changed something in BIOS?

Exit without saving by pressing Escape or the key shown on screen and selecting "Discard Changes". Your computer will restart normally and the change won't take effect. If you already saved the change and your computer won't start, restart and enter BIOS again to change it back, or reset BIOS to factory defaults.

Is it safe to update BIOS?

BIOS updates can fix security issues and hardware compatibility problems, but they carry a small risk — if the power goes out during the update, your computer may not start again. Only update BIOS if your computer is plugged in, the battery is fully charged (on a laptop), and you have a specific reason to update. Check your manufacturer's website to see if an update is available and what it fixes.