The BIOS is low-level firmware that initializes hardware at startup, acts as an interface between hardware and OS, and retains settings via CMOS battery. It performs POST to check hardware, identifies bootable drives, and configures components like memory, ports, and slots. BIOS settings can be accessed during boot by pressing a key like F2 or DEL. Newer UEFI firmware improves on BIOS but still relies on it for configuration, POST, and setup.

1. BIOS Configuration

2. What is a BIOS?
 Basic input/output system is a type of firmware
used to perform hardware initialization during
the boot process (power-on startup) on IBM PC
compatible computers, and to provide runtime
services for operating systems and programs.
 Consist of low-level software that controls the
system hardware and acts as an interface
between the operating system (OS) and the
hardware

3.  Commonly BIOS is preloaded into a read-only memory (ROM) such in the
image below

4.  The settings of the BIOS are being retained by the use of a CMOS
(Complementary Metal-Oxide-Semiconductor) battery.

5. What is the function of the BIOS?
1. Perform power-on self-test (POST) that check the status of the hardware is operating
correctly.
If the computer is functioning properly a single beep will be heard. If there is a hardware
problem a series of beep will be heard. (Beep Codes and Meaning will be discussed in
Maintenance Chapter)

6. What is the function of the BIOS?
2. The BIOS identifies which drive are available.
3. The BIOS identifies which drive are bootable
4. How the memory is configured.
5. How PCIe and PCI expansion slots are configured
6. How SATA and USB ports are configured
7. Motherboard power management features

7. More recently the BIOS has been improved by a specification called the Unified
Extensible Firmware Interface (UEFI), which specifies a different software interface for
boot and runtime services but still relies on the traditional BIOS for system configuration,
power-on self-test (POST), and Setup.

8. How to enter BIOS in Windows
 Method : Use hotkey during boot-up
 Acer: F2 or DEL
 ASUS: F2 for all PCs, F2 or DEL for motherboards
 Dell: F2 or F12
 HP: ESC or F10
 Lenovo: F2 or Fn + F2
 Lenovo (Desktops): F1
 Lenovo (ThinkPads): Enter + F1.
 MSI: DEL for motherboards and PCs
 Microsoft Surface Tablets: Press and hold volume
up button.
 Origin PC: F2
 Samsung: F2
 Sony: F1, F2, or F3
 Toshiba: F2

9. Reference:
 https://www.hp.com/us-en/shop/tech-takes/how-to-enter-bios-setup-
windows-pcs
 https://www.youtube.com/watch?v=LGz0Io_dh_I
 https://www.youtube.com/watch?v=9GblKZO-smU