The fastest way to enter BIOS depends on your computer's manufacturer

To enter BIOS, you restart your computer and press a specific key during startup — before Windows or macOS loads. The key varies by manufacturer: Dell and Lenovo machines usually respond to F2, HP and Compaq to F10, Asus to Delete, and some older systems to F1 or F12. On a Mac, hold Command + Option + P + R during startup to reset the firmware settings, though modern Macs use a different system called Secure Boot that you access through System Settings instead.

The timing matters: you need to press the key repeatedly as soon as you power on the computer, before the manufacturer's logo disappears. If you miss the window, restart and try again. Some computers show a brief message on the startup screen telling you which key to press — watch for text like "Press F2 to enter Setup" or "Press Del for BIOS."

If you are not sure which key your computer uses, check the manual that came with it, or search your computer model number plus "BIOS key" online. Manufacturer support pages list this for every model they make.

Key Takeaways

  • BIOS is accessed by restarting your computer and pressing a specific key during startup, usually F2, F10, or Delete depending on the manufacturer.
  • You must press the key repeatedly as the computer powers on, before the operating system loads, or you will miss the window and have to restart.
  • Common reasons to enter BIOS include changing boot order, enabling or disabling hardware, checking system temperature, and updating the BIOS itself.
  • BIOS changes affect how your hardware behaves at the deepest level, so only change settings if you understand what they do or are following specific instructions.

Why you might need to enter BIOS

BIOS controls how your computer's hardware initializes before the operating system takes over. Most users never need to touch it, but certain tasks require BIOS access. The most common reason is changing the boot order — the sequence in which your computer checks devices for an operating system. If you are installing Windows or Linux from a USB drive, you may need to tell BIOS to check the USB port before the hard drive.

Other reasons include enabling or disabling built-in hardware like the camera, microphone, or USB ports; checking system temperatures and fan speeds; updating the BIOS itself when a manufacturer releases a patch; and troubleshooting hardware that the operating system does not recognize. Some users also enter BIOS to enable or disable virtualization features for running virtual machines, or to change how much RAM the system recognizes.

If you are not sure whether you need BIOS access, you probably do not. A support technician or installation guide will tell you explicitly if BIOS changes are necessary for what you are trying to do.

What you see when BIOS opens

BIOS displays a text-based menu, usually with a dark background and light text — it looks nothing like Windows or macOS. The layout varies by manufacturer, but most organize settings into tabs or categories you navigate with arrow keys and Enter. You will see sections like "Main" (showing your CPU, RAM, and storage devices), "Boot" (where you change boot order), "Security" (for passwords and secure boot settings), and "Exit" (to save and restart).

The interface is intentionally simple because it runs before any operating system loads. You cannot use a mouse in most BIOS menus — navigation is keyboard-only, using arrow keys, Enter, and sometimes Escape or F-keys to move between sections. Each setting usually has a description or help text explaining what it does, though the language is technical.

Do not panic if the screen looks unfamiliar. You are not breaking anything by looking around. As long as you do not change settings and save them, exiting BIOS leaves your computer unchanged. Press Escape or select "Exit Without Saving" to leave without making changes.

How to change boot order in BIOS

Boot order is the most common BIOS change for everyday users. Navigate to the "Boot" tab using arrow keys, and you will see a list of devices in the order your computer checks them for an operating system — usually "Hard Drive," "USB," "CD/DVD," or similar. To boot from a USB drive (for installing an operating system or running a repair tool), move USB to the top of the list.

Use the arrow keys to highlight the device you want to move, then press Enter or look for an on-screen prompt telling you which key to press to move it up or down. Once USB is first, press F10 or select "Save and Exit" to restart. Your computer will now check the USB drive first when it powers on.

After you finish installing or repairing, go back into BIOS and move your hard drive back to the top so the computer boots normally. If you leave USB first and no bootable USB is plugged in, the computer will move to the next device in the list, so it will still work — but it is cleaner to restore the original order.

BIOS passwords and security settings

BIOS can be password-protected, preventing anyone without the password from entering BIOS or booting from devices other than the hard drive. If you set a BIOS password and forget it, you cannot simply reset it from Windows — you would need to contact the manufacturer or have a technician reset it physically, which usually requires opening the computer case.

Do not set a BIOS password unless you have a specific reason to lock down your computer, such as protecting a shared work machine. If you do set one, write it down and store it somewhere safe. Some manufacturers allow you to set two passwords: one to enter BIOS and one to change BIOS settings, so someone could view settings without changing them.

The "Secure Boot" setting in BIOS controls whether your computer will only boot operating systems signed by Microsoft or other trusted vendors. This is a security feature that prevents some types of malware from running at startup, but it can prevent you from installing certain Linux distributions or older operating systems. Most users should leave Secure Boot enabled.

Updating BIOS safely

Manufacturers occasionally release BIOS updates to fix bugs, improve hardware compatibility, or patch security issues. You can check whether an update is available by visiting the manufacturer's support page for your computer model and looking for "BIOS" or "Firmware" downloads.

BIOS updates are risky if something goes wrong during the update — a power loss or interruption can leave your computer unable to start. Only update BIOS if the update addresses a specific problem you are experiencing, or if the manufacturer strongly recommends it for security reasons. Before updating, make sure your computer is plugged into power and will not go to sleep, and close all other programs.

Most manufacturers provide a tool that runs from Windows to update BIOS, rather than requiring you to update from within BIOS itself. Follow the manufacturer's instructions exactly, and do not restart the computer or interrupt the process once it begins. After the update completes, your computer will restart and BIOS will be updated.

Common BIOS settings explained

CPU temperature: Shows how hot your processor is running. Normal range is 30 to 70 degrees Celsius at idle, and up to 90 degrees under heavy load. If temperatures are consistently above 80 degrees, your computer may need cleaning or better cooling.

RAM: Displays how much memory your computer detects. If you installed new RAM but BIOS shows the old amount, the new RAM may not be fully seated in its slot — power off and reseat it.

Storage devices: Lists hard drives and SSDs BIOS can see. If a drive you installed does not appear, it may not be connected properly or may need a driver.

Virtualization: Allows your computer to run virtual machines. Enable this only if you plan to use software like VirtualBox or Hyper-V.

XMP or DOCP: Overclocking profiles for RAM that increase speed beyond standard specifications. Leave this disabled unless you are intentionally overclocking.

Frequently Asked Questions

What happens if I change a BIOS setting and do not know what it does?

You can always exit BIOS without saving your changes by pressing Escape or selecting "Exit Without Saving." If you already saved a change and your computer is not working properly, restart and enter BIOS again, find the setting you changed, and restore it to its default value. Most BIOS menus have a "Load Defaults" or "Reset to Factory Settings" option that restores everything at once.

Can I access BIOS from Windows without restarting?

On Windows 10 and 11, you can restart directly into BIOS by going to Settings > System > Recovery, clicking "Restart now" under "Advanced startup," and selecting "Troubleshoot" > "Advanced options" > "UEFI Firmware Settings." This is faster than repeatedly pressing a key during startup, but the traditional method works on any computer.

Is it safe to change BIOS settings?

BIOS changes affect how your hardware behaves, so incorrect changes can prevent your computer from starting or cause hardware to malfunction. Only change settings if you understand what they do or are following specific instructions from a support technician or installation guide. Most everyday users should never need to change BIOS settings.

What if my computer will not let me enter BIOS?

Some computers, especially newer ones with Secure Boot enabled, may not respond to the standard BIOS key. Check your computer's manual or the manufacturer's support page for your specific model. If BIOS is password-protected and you do not know the password, you will need to contact the manufacturer or a technician.