What BIOS Is and Why You Might Need It
BIOS (Basic Input/Output System) is the firmware that runs before your operating system loads. It controls hardware settings like boot order, fan speed, and security features. You enter BIOS when you need to change how your computer starts up, troubleshoot hardware problems, or adjust system settings that Windows or macOS cannot reach.
The steps to enter BIOS differ by computer manufacturer and age. Most commonly, you press a specific key during startup — before Windows or macOS appears on screen. The key varies: Dell uses F2, HP and Lenovo often use F10, Asus uses Delete, and some older systems use F1 or F12. If you press the wrong key or press it too late, your operating system will load normally and you'll have to restart and try again.
Key Takeaways
- BIOS is accessed by pressing a specific key during the first few seconds after you power on your computer, before the operating system loads.
- The correct key depends on your computer's manufacturer — Dell typically uses F2, HP and Lenovo use F10, and Asus uses Delete.
- You must press the key repeatedly and quickly; if you wait too long or miss the window, your computer will boot normally and you'll need to restart.
- Once in BIOS, use arrow keys to navigate and Enter to select options; look for an Exit or Save and Exit option to leave without making changes.
- If you don't know your manufacturer or the correct key, restart and watch for a message on the startup screen that tells you which key to press.
Identify Your Computer Manufacturer and Model
The key you need to press depends on who made your computer. Check the bottom or back of your laptop, or look inside the desktop case near the motherboard. Common manufacturers include Dell, HP, Lenovo, Asus, Acer, and MSI. If you built the computer yourself, the motherboard brand (not the case brand) determines the key.
You can also find this information in Windows by opening Settings, clicking System, and scrolling to "About." Look for "System manufacturer" and "System model." Write down both before you restart, because you won't be able to look them up once the startup process begins.
Restart Your Computer and Watch the Startup Screen
Save any open work and close all programs. Click the Start menu, hold Shift, and click Power, then Restart. Your computer will shut down and turn back on. As soon as you see the manufacturer's logo or a black screen with text, watch for a message that says something like "Press F2 to enter Setup" or "Press Delete for BIOS."
This message usually appears for only a few seconds. If you see it, you now know the correct key. If you don't see a message, use the key that matches your manufacturer from the table below. You may need to restart several times to get the timing right — it's common to press too early (before anything appears) or too late (after the operating system has already started loading).
Press the Correct Key at the Right Time
Power on your computer or restart it if it's already running. The moment you see the manufacturer logo or any text on a black screen, begin pressing your key repeatedly — not just once, but several times per second. Press and release, press and release. Do not hold it down continuously.
You have roughly 2 to 5 seconds before the operating system takes over. If you see a blue or black screen with white text and menu options, you've entered BIOS successfully. If Windows or macOS loads instead, you pressed the key too late or the wrong key. Restart and try again, pressing earlier this time.
| Manufacturer | Common BIOS Key | Alternate Keys to Try |
|---|---|---|
| Dell | F2 | F12, Delete |
| HP / Hewlett-Packard | F10 | F2, Esc |
| Lenovo | F10 or F2 | Delete, Fn + F2 |
| Asus | Delete | F2 |
| Acer | Delete or F2 | F1 |
| MSI | Delete | F2 |
| Apple (Mac) | Command + R (Recovery) | Option (firmware settings on newer Macs) |
Navigate BIOS Using Your Keyboard
Once you're in BIOS, you'll see a menu with options like Main, Advanced, Boot, Security, and Exit. Use the arrow keys on your keyboard to move between menu items. Press the right arrow to open a submenu and the left arrow to go back. Press Enter to select an option or change a setting.
Do not make changes unless you know exactly what you're changing. BIOS settings control core hardware functions, and incorrect changes can prevent your computer from starting. If you entered BIOS just to see it or to check a setting, you can leave without saving by pressing Escape or finding the Exit menu and selecting "Exit Without Saving."
Exit BIOS Without Making Changes
If you've made no changes and want to leave, look for an "Exit" menu option or press Escape. Select "Exit Without Saving" or "Discard Changes and Exit." Your computer will restart and load your operating system normally. Nothing you viewed in BIOS affects your system unless you explicitly saved a change.
If you did make changes and want to keep them, look for "Save and Exit" or "Save Changes and Exit." BIOS will ask you to confirm. Press Enter to confirm, and your computer will restart with the new settings active. If you change your mind after saving, you can always restart and enter BIOS again to change the settings back.
Troubleshooting When You Can't Enter BIOS
If you've tried the correct key multiple times and still can't enter BIOS, the timing may be too tight on your computer. Try pressing the key as soon as you press the power button, before anything appears on screen. On some newer computers, especially laptops, you may need to hold the key down for a full second rather than tapping it repeatedly.
If your computer has a BIOS password set, you'll see a password prompt before entering the main menu. If you don't know the password, you may need to reset it. This usually requires opening the computer case and removing a small battery from the motherboard for 10 to 15 seconds, or moving a jumper on the motherboard. Consult your computer's manual or contact the manufacturer for specific instructions, as the process varies widely.
Frequently Asked Questions
What's the difference between BIOS and UEFI?
UEFI (Unified Extensible Firmware Interface) is the modern replacement for BIOS. It works the same way — you enter it during startup by pressing a key — but it has a graphical interface and supports larger hard drives. Most computers made after 2010 use UEFI, though it's often still called "BIOS" in everyday language. The steps to enter it are identical.
Can I damage my computer by entering BIOS?
Entering BIOS and looking around causes no damage. Changing settings can cause problems if you don't know what you're doing — for example, disabling a required device or changing boot order incorrectly. If you only view settings and exit without saving, your computer is unaffected.
Why does my computer keep booting to BIOS instead of Windows?
This usually means the boot order is set incorrectly. In BIOS, find the Boot menu and check that your hard drive is listed first. If a USB drive or CD drive is first, your computer tries to boot from that device instead of your hard drive. Move your hard drive to the top of the list and save the changes.
Do I need to enter BIOS to install Windows?
Yes, if you're installing Windows from a USB drive or DVD. You need to change the boot order in BIOS so your computer boots from the USB or DVD first. Once Windows is installed, change the boot order back so your computer boots from the hard drive normally.
What if I forgot my BIOS password?
Most consumer computers allow you to reset the BIOS password by removing the CMOS battery from the motherboard for 10 to 15 seconds, which clears all BIOS settings. Some newer computers have a jumper on the motherboard instead. Check your computer's manual for the exact location and procedure, as it varies by model.