What resetting your BIOS does and when you need it

Resetting your BIOS (Basic Input/Output System) restores all the settings that control how your computer's hardware starts up and runs. Your BIOS is the firmware that sits between your operating system and your physical hardware — it tells your motherboard how to initialize your CPU, RAM, storage drives, and other components before Windows or macOS even loads.

Most people never touch BIOS settings. But if you've changed something in BIOS and your computer won't start, or if you're troubleshooting a hardware problem and someone told you to reset BIOS to defaults, you need to know how. A reset clears any custom settings you or someone else made and returns everything to what the manufacturer set originally.

This is different from a factory reset of your operating system — BIOS reset happens at a lower level and won't erase your files or programs. It only affects how your hardware initializes.

Key Takeaways

  • A BIOS reset returns all hardware initialization settings to factory defaults without touching your files or operating system.
  • The easiest method on most modern computers is to enter BIOS setup during startup and select the reset or restore defaults option from the menu.
  • If your computer won't start at all, you can remove the CMOS battery from the motherboard for 10 to 15 minutes to force a hardware reset.
  • You will need to restart your computer and press a specific key (usually Delete, F2, F10, or F12) immediately after power-on to enter BIOS setup.
  • After resetting BIOS, you may need to adjust settings like boot order or enable XMP if you had custom performance settings before.

Entering BIOS setup on your computer

To reset BIOS, you first have to get into the BIOS setup menu. This happens before your operating system loads, so timing matters. Restart your computer completely, then watch the screen carefully as it powers back on.

Immediately after you see the manufacturer logo (Dell, HP, Lenovo, ASUS, etc.), start pressing a specific key repeatedly. The key varies by manufacturer: Delete is most common on desktop computers, but laptops and some desktops use F2, F10, or F12. Some computers show the correct key on the startup screen itself — look for text that says "Press [key] to enter Setup" or "Press [key] for BIOS."

If you miss the window, let the computer finish booting into Windows or macOS, then restart and try again. You typically have only 2 to 3 seconds to press the key before the operating system starts loading.

Finding and selecting the reset option in BIOS

Once you're in the BIOS setup menu, you'll see a text-based interface with several tabs or menu options. The exact layout depends on your motherboard manufacturer (ASUS, MSI, Gigabyte, Intel, etc.), but the reset option is usually in one of these locations: a tab labeled "Exit," "Save & Exit," "Defaults," or "Tools."

Look for an option that says "Load Defaults," "Restore Defaults," "Reset to Defaults," or "Load Setup Defaults." Some BIOS versions call it "Load Optimal Defaults" or "Load Factory Defaults." Highlight that option using your arrow keys and press Enter.

The BIOS will ask you to confirm — usually with a yes/no prompt. Select yes or confirm. The system will then reset all settings and may restart automatically. Do not turn off your computer during this process.

Resetting BIOS by removing the CMOS battery

If your computer won't start at all, or if you can't access the BIOS setup menu, you can force a hardware reset by removing the CMOS battery. This is a small coin-shaped battery on the motherboard that stores BIOS settings even when the computer is powered off. Removing it for a few minutes clears those settings.

Before you open your computer: Power it off completely, unplug the power cable from the wall, and wait 30 seconds. This ensures no power is flowing to the motherboard. If your computer has a removable side panel, open it. If it's a laptop, you may need to remove the keyboard or bottom panel — consult your laptop's manual or search "[your laptop model] CMOS battery removal" online.

Locate the CMOS battery on the motherboard — it's a round, flat battery about the size of a dime, usually silver-colored. Gently press down on the clip holding it in place and slide the battery out. Leave it out for 10 to 15 minutes. Then slide it back in until you hear or feel it click into place.

Close the panel, plug the power cable back in, and power on your computer. The BIOS will have reset to factory defaults. You may see a message on startup saying the BIOS has been reset or that the date and time are incorrect — this is normal.

What to do after resetting BIOS

After a BIOS reset, your computer should start normally and your operating system will load as usual. Your files, programs, and Windows or macOS installation are untouched. However, you may notice a few changes.

The system date and time may be wrong — set them correctly in your operating system settings. If you had custom hardware settings before the reset (like XMP for RAM overclocking, or a custom boot order), those are gone and you'll need to reconfigure them if you want them back. Check that your storage drives appear in the correct order if you have multiple drives.

If the reason you reset BIOS was to fix a startup problem, test whether the computer now starts reliably. If it still won't start, the problem may be hardware-related rather than a BIOS setting issue.

Common mistakes to avoid

The biggest mistake is turning off the computer while BIOS is resetting or while you're in the setup menu. This can corrupt the BIOS itself and make the problem worse. Let any reset process complete fully, even if it seems to take a long time.

Another common error is pressing the wrong key to enter BIOS. If you're not sure which key your computer uses, search "[your computer model] enter BIOS" online before you restart. Pressing the wrong key just boots normally into Windows or macOS, wasting time.

If you remove the CMOS battery, don't force it out — if the clip is tight, gently wiggle the battery side to side while pressing the clip. Forcing it can damage the battery socket on the motherboard. Also, make sure the computer is completely unplugged before you touch any internal components.

When to try something else instead

A BIOS reset is the right move if you changed a BIOS setting and the computer won't start, or if someone told you to reset BIOS as a troubleshooting step. It's also worth trying if your computer is behaving strangely and you suspect a BIOS setting got changed accidentally.

But if your computer won't start and you never changed any BIOS settings, the problem is probably hardware failure (a dead hard drive, bad RAM, or failed power supply) rather than a BIOS issue. In that case, resetting BIOS won't help. If resetting BIOS doesn't fix the startup problem, you're likely dealing with hardware damage and should contact a repair technician or the manufacturer.

If you're trying to fix a slow computer or a software problem (like Windows won't load, or a program keeps crashing), a BIOS reset won't help. Those problems need a different approach — usually a Windows repair, a clean reinstall, or troubleshooting the specific program.

Frequently Asked Questions

Will resetting BIOS erase my files or programs?

No. BIOS reset only affects hardware initialization settings. Your files, programs, and operating system remain completely untouched. You won't lose anything on your hard drive or SSD.

What if I can't find the CMOS battery on my motherboard?

If you have a desktop computer, search "[your motherboard model] CMOS battery location" online — the manual or a forum post will show you exactly where it is. If you have a laptop, the battery may be under the keyboard or in a compartment under the bottom panel. Laptop manuals usually show this. If you're uncomfortable opening your computer, take it to a repair shop instead.

Do I need to change any BIOS settings after I reset it?

Not usually. Factory defaults work for most people. However, if you had custom settings before (like XMP for RAM speed, or a specific boot order), you'll need to set those again if you want them back. Check your notes or search your motherboard model to see what settings are recommended for your hardware.

How long does a BIOS reset take?

Entering BIOS and selecting reset takes a few minutes. The actual reset process is usually instant or takes less than a minute. If you're removing the CMOS battery, the whole process (opening the computer, removing the battery, waiting, reinstalling it, closing it up) takes 15 to 30 minutes depending on how easy your computer is to open.

What if my computer still won't start after I reset BIOS?

If resetting BIOS doesn't fix a startup problem, the issue is likely hardware failure — a dead hard drive, bad RAM, or a failed power supply. Try reseating your RAM (removing it and pushing it back in firmly) or checking that all power cables are connected. If that doesn't work, contact the manufacturer or a repair technician.