What BIOS is and why you might need to enter it

BIOS (Basic Input/Output System) is firmware that runs before your operating system loads. It controls hardware settings like boot order, fan speed, and RAM detection. Most people never need to enter BIOS, but you may need to if you're troubleshooting hardware problems, changing which drive your computer boots from, or updating BIOS itself.

The process differs slightly depending on whether you have a Windows PC, Mac, or Linux machine, and which manufacturer made your motherboard. The timing is critical—you have to press a specific key during a narrow window when the computer is starting up, before Windows or macOS loads.

Key Takeaways

  • You enter BIOS by restarting your computer and pressing a specific key during startup—usually Delete, F2, F10, or F12, depending on your motherboard manufacturer.
  • The key press window lasts only a few seconds, so you need to restart the computer first and then begin pressing the key when ready as it powers on.
  • On Windows, you can also reach BIOS through Settings without restarting, though the traditional restart method works on all machines.
  • If you press the wrong key or miss the window, your computer will boot normally into Windows or macOS, and you can straightforward restart and try again.
  • Changing BIOS settings incorrectly can prevent your computer from starting, so only change settings if you know what they do.

Finding the correct BIOS key for your computer

The key you need to press depends on who made your motherboard, not your operating system. Common BIOS keys are Delete, F2, F10, and F12. Most computers display a message on the startup screen that says "Press [key] to enter Setup" or "Press [key] for BIOS"—watch for this message when you restart.

If you don't see a message, check your computer's manual or the manufacturer's website. Search for your motherboard model plus "BIOS key" or "enter setup". Common motherboard makers include ASUS, MSI, Gigabyte, and Intel. Laptop manufacturers like Dell, HP, and Lenovo also have their own BIOS keys—Dell often uses F2, HP often uses F10, and Lenovo often uses F2 or Fn+F2.

Write down the key before you restart, so you don't have to hunt for it while the startup window is open.

Restarting your computer and pressing the BIOS key

Restart your computer normally. As soon as the screen goes black and you see the first startup logo or text, begin pressing your BIOS key repeatedly—about once per second. Do not wait for the Windows or macOS login screen to appear. You are aiming to interrupt the boot process before the operating system loads.

If you see the BIOS screen (usually a blue or dark background with white text and menus), you have succeeded. If Windows or macOS loads instead, your computer has booted normally. Restart again and try pressing the key earlier or more frequently.

Some computers require you to hold the key down rather than tap it. If tapping does not work, try holding the key from the moment you see the first logo until the BIOS screen appears.

Entering BIOS on Windows without restarting

Windows 10 and 11 offer a faster route: you can reach BIOS settings through the Settings app without restarting. Open Settings, go to System, then select Recovery. Under "Advanced startup," click "Restart now." Your computer will restart into a blue menu. Select "Troubleshoot," then "Advanced options," then "UEFI Firmware Settings." Click "Restart," and your computer will boot into BIOS.

This method is more reliable than the key-press method because you do not have to time a key press. However, it only works on Windows 10 and 11 with UEFI firmware (most modern computers have this). Older systems or those with legacy BIOS may require the restart-and-key-press method instead.

What to do if you cannot reach BIOS

If you have tried the key press multiple times and still see Windows or macOS loading, you may have the wrong key. Double-check your motherboard or computer model and search again for the correct BIOS key. Some computers require you to hold down the key from the moment you press the power button, rather than waiting for the logo to appear.

If your computer has a BIOS password set, you will be prompted to enter it before you can access BIOS settings. If you do not know the password, you may need to contact the computer's manufacturer or a technician, as there is no standard way to bypass a BIOS password.

If your computer will not start at all—it powers on but shows no logo or text—the problem is likely hardware-related rather than BIOS access. In this case, contact a technician or the manufacturer.

Common BIOS settings and what they control

Once you are in BIOS, you will see menus for different hardware settings. The most commonly changed settings are boot order (which drive the computer tries to start from first), fan speed, and RAM detection. Other settings control things like USB ports, network boot, and virtualization features.

Use arrow keys to navigate BIOS menus and Enter to select options. Look for an "Exit" or "Save and Exit" option when you are done. If you change a setting and want to undo it, most BIOS screens have a "Load Defaults" or "Reset to Defaults" option. Do not change settings unless you understand what they do, as incorrect changes can prevent your computer from starting.

Exiting BIOS and returning to your operating system

To leave BIOS without saving changes, look for an "Exit Without Saving" or "Discard Changes and Exit" option. Your computer will restart and boot normally into Windows or macOS. To save changes you have made, select "Save and Exit" or "Save Changes and Exit." Your computer will restart with the new settings in place.

After you exit BIOS, your computer will boot into your operating system as usual. If you changed boot order or other critical settings, the startup process may take longer than normal, or your computer may behave differently. This is usually temporary while the system adjusts to the new settings.

Frequently Asked Questions

What happens if I press the wrong key during startup?

Your computer will straightforward boot normally into Windows or macOS. You have not damaged anything. Restart the computer and try the correct key. There is no penalty for pressing the wrong key.

Can I damage my computer by changing BIOS settings?

Yes, if you change settings you do not understand. Incorrect BIOS changes can prevent your computer from starting. Most BIOS screens have a "Load Defaults" option that restores safe settings. If your computer will not start after a BIOS change, restart and enter BIOS again, then select "Load Defaults" and save.

Do I need to enter BIOS to install a new hard drive or SSD?

Not always. Most modern computers detect new drives automatically. However, if your computer does not recognize the new drive, you may need to enter BIOS and check that the drive is enabled or change the boot order. Check your drive manufacturer's instructions first.

Is BIOS the same as UEFI?

UEFI is the modern replacement for BIOS, but the terms are often used interchangeably. The process for entering UEFI is the same as entering BIOS—restart and press the setup key. UEFI screens usually look more modern with graphics and a mouse pointer, while older BIOS screens are text-only.

Why does my computer keep asking me to enter BIOS?

This usually means a BIOS setting is incorrect, often the boot order. If no bootable drive is found, your computer will prompt you to enter BIOS. Check that your main hard drive is listed first in the boot order. If you recently installed a new drive, make sure the old drive is still listed and set to boot first.