Resetting the BIOS or CMOS returns your motherboard's firmware settings to their factory defaults, and it's one of the most useful troubleshooting steps for boot failures, failed overclocks, or a PC that's simply stopped behaving predictably after a settings change. This guide covers the three main ways to do it, from the simplest software option to the more hands-on hardware methods needed when the PC won't boot at all.

When You'd Need to Reset BIOS/CMOS

  • The PC won't POST or boot after enabling an overclock, XMP/EXPO profile, or changing another BIOS setting
  • You're troubleshooting a no-display or restart-loop issue and want to eliminate misconfigured settings as a cause
  • You've forgotten a BIOS supervisor password
  • You've bought a used motherboard and want to start from a clean, known configuration
  • Settings keep reverting unexpectedly, suggesting a dying CMOS battery (see our dedicated guide on CMOS battery problems)

Warning: Resetting CMOS will erase all custom settings, including boot order, fan curves, XMP/EXPO profiles and any BIOS password. Note down any critical custom settings beforehand if you can still access the BIOS menu, since you'll need to reconfigure them afterwards.

Method 1: Reset From Within the BIOS Menu (Software Reset)

Use this method whenever the PC still boots into the BIOS/UEFI setup screen normally — it's the simplest and safest option.

  1. Restart the PC and press the key to enter BIOS/UEFI setup during boot — commonly Del, F2, F10 or Esc, shown briefly on the manufacturer's splash screen.
  2. Look for an option called Load Setup Defaults, Load Optimised Defaults, or Reset to Default, usually found on the main screen or under an Exit/Save menu.
  3. Confirm the prompt, then choose Save Changes and Exit (often F10).
  4. The PC will restart with all settings back to factory default.

This method is quick, requires no case opening, and is the right first attempt for most everyday BIOS troubleshooting.

Method 2: Using the Clear CMOS Button or Jumper

Use this when the PC won't boot far enough to reach the BIOS menu — for example, after an unstable overclock causes a black screen or restart loop before POST completes.

If Your Motherboard Has a Clear CMOS Button

Higher-end motherboards, particularly on the rear I/O panel, sometimes include a dedicated Clear CMOS button.

  1. With the PC fully shut down (it's fine to leave it plugged in for this method on boards with a rear button, since the button typically works with standby power — check your manual to confirm), press and hold the Clear CMOS button for 3–5 seconds.
  2. Power on the PC as normal; it will boot with default settings.

If Your Motherboard Has a Clear CMOS Jumper

More common on mid-range and budget boards, this is a small set of three pins, usually labelled "CLR_CMOS" or similar, near the CMOS battery.

  1. Shut down the PC fully and unplug the power cable from the wall.
  2. Earth yourself with an anti-static wrist strap.
  3. Open the case and locate the jumper — check your motherboard manual for its exact position, as it varies by model.
  4. Note the pins' current position (usually covering pins 1–2, the default operating position).
  5. Move the jumper cap to cover pins 2–3 instead, wait about 5–10 seconds, then move it back to cover pins 1–2.
  6. Reconnect power and boot — settings will be reset to default.

Pro tip: Always consult your specific motherboard's manual (downloadable free from the manufacturer's support page using your exact model number) before using the jumper method — pin layouts and labelling vary between manufacturers, and using the wrong jumper could affect a different function entirely.

Method 3: Removing the CMOS Battery

Use this as a reliable fallback if your board has no jumper or button you can locate, or as part of replacing a genuinely failing battery.

  1. Shut down fully, unplug the power cable, and press the power button for 5 seconds to discharge residual power.
  2. Earth yourself before opening the case.
  3. Locate the round CR2032 coin-cell battery on the motherboard.
  4. Gently push the retention clip aside and remove the battery, noting its orientation.
  5. Leave it out for 5–10 minutes (some sources suggest longer for very stubborn resets, but a few minutes is sufficient for CMOS to fully discharge on most boards).
  6. Reinsert the battery the same way round it came out, with the retention clip clicking back into place.
  7. Reconnect power and boot.

Safety note: Always fully unplug the PC from the mains, not just switch it off, before opening the case for any of these methods, and always earth yourself first. Static discharge can permanently damage motherboard components, and working inside a case with power still connected risks both you and the hardware.

After Resetting: What to Reconfigure

Once back in the BIOS after any of these methods, you'll typically need to reset:

  1. Boot order — set your Windows drive as the first boot device (Boot menu section).
  2. XMP/EXPO memory profile — re-enable this to run RAM at its rated speed rather than the slower JEDEC default (usually under an Ai Tweaker, OC, or Memory section, labelled differently by manufacturer).
  3. Date and time — often reset to a default value; Windows will usually correct this automatically once booted if internet time sync is enabled.
  4. Secure Boot and TPM/fTPM — re-enable if required for Windows 11 (usually under a Security section).
  5. Fan curves — reapply any custom fan profiles you'd previously configured, as these revert to default (often more conservative and louder) after a CMOS reset.

Once these are reconfigured, save and exit, and confirm the PC boots into Windows normally. If a reset was performed to troubleshoot instability and the problem persists even at default settings, this points away from a BIOS misconfiguration and towards a hardware fault worth investigating separately — RAM, GPU seating, or the PSU are the next things worth checking.

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