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CMOS, BIOS configuration


CMOS is known as Complementary Metal Oxide Semiconductor. This hardware is used on the motherboard. CMOS is a memory that stores information about BIOS settings. It also stores information about system date and time as well as hardware settings.

CMOS is a battery used in the motherboard. CMOS battery lifetime is 10 years in a proper environment.

Therefore, CMOS is a battery as well as memory. CMOS and BIOS work together in a computer system.

Resetting CMOS

Resetting CMOS is a troubleshooting tip for some problems. You can use the three easiest steps to reset a CMOS.


In the first method, you need to enter in BIOS setup utility. Inside the BIOS setup utility, you can find Reset BIOS setting or Setup default to load factory default value.


In the second method, you can remove the CMOS from the motherboard and wait for few minutes. By removing CMOS from motherboard you can reset the CMOS data. After a few minutes place the CMOS on the motherboard properly.


The third method, find the CMOS jumper on the motherboard. Near the jumper, you can find some text like CLEAR, PASSWORD, CLRPWD, etc. By changing the jumper position properly, you can reset your CMOS settings.


BIOS is known as the Basic Input Output System. It is a software located on the motherboard. The manufacturer saved BIOS software inside the BIOS ROM or BIOS IC or BIOS chips.

BIOS is a software.

BIOS ROM or BIOS IC, or BIOS chips is hardware.

The BIOS helps to boot your computer. BIOS instructions are responsible for the POST (Power-On Self-Test) during booting. During POST it checks all the hardware that connected with the motherboard.

You can hear single beep sound as a confirmation message that POST is performed successfully. There is no problem with your computer. More than one beep or continuous long beep means some issues on your computer.

How to open BIOS utility?

We don’t have any fixed key to access or open the BIOS menu or utility. This is depending on the manufacturer. Some commons keys to enter BIOS utility are F1, F2, F10, Delete, Esc, etc.

First, start your computer. If your computer is already running restart the computer. And, check your computer screen which buttons need to press to open BIOS.

Second, press the key to open BIOS before loading the OS. If OS is loaded than again restart the computer and proceed.

Important, BIOS utility can open during POST only.

BIOS configuration

You can have different BIOS configuration options from the BIOS menu. Some common configurations are

  1. Change the date and time.
  2. Load BIOS setup default.
  3. Change the boot order.
  4. Create a BIOS password.
  5. Enable or disable RAID.
  6. Change hard drive settings.
  7. Enable or disable the POST.
  8. Enable or disable onboard USB.
  9. Change power-on settings.
  10. View system and CPU temperature.
  11. Enable or disable ACPI.
  12. Enable or disable onboard Audio.
  13. View FAN speed.

CMOS and BIOS together

CMOS and BIOS work together. All the BIOS configuration settings are saved automatically inside the CMOS.

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