What Is BIOS (Basic Input/Output System) and How To Access and Use?

Basic Input and Output System simply know as BIOS is the first thing that is loaded by the computer. BIOS is designed to initialize a computer properly and load the real full features operation system like Windows, Linux, etc. BIOS is a low-level software where it provides very little but crucial features for its users.

BIOS Functions

BIOS has some basic functions in order to start the computer and load the real operating system properly.

POST is a function that is very important because BIOS will check the hardware and connected peripherals and loads them properly for the operating systems. POST is the first thing a BIOS does when the computer is started. When the POST start we can hear a beep sound which says the POST is started.
Bootstrap Loader will locate and load a real operating system. Actually, BIOS is also an operating system with very restricted features. BIOS will start the load chain for different operating systems like Linux, Windows, BSD, etc.
Load Drivers will load basic drivers for the hardware. These drivers mainly designed to manage given hardware and pass this hardware into the real operating system.
System and Hardware Configuration will set some basic configuration about the system like System Time, Boot Preferences, Security, Hardware Features etc.

How To Update BIOS?

BIOS software is stored in an EPROM which is not easy to change the content of the BIOS chip. But there are some tools provided by the mainboard or chip manufacturer in order to update the BIOS. BIOS Update sometimes called Flash BIOS because it will flash the BIOS chip. Here the steps required to update the BIOS. Keep in mind this is a fragile process and do not interrupt which will cause the BIOS corrupt.

The download recent BIOS firmware from the chip or mainboard manufacturer.
Copy BIOS update software to the USB storage.
Boot to BIOS and Navigate to the Tool-> EZ Flash.
Select USB and then select the BIOS update file.
You will be prompted one final time before applying the update. Review and Accept this.
Reboot upon completion.

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BIOS vs Operating System

As stated previously BIOS is an operating system but it is very different from full-fledged real operating systems. In this part, we will compare the BIOS and Real operating systems.

BIOS is the first OS which starts the computer but Real Operating system starts after BIOS
BIOS initializes hardware and peripherals where a Real Operating system uses hardware and peripherals.
BIOS has very low-level functions where the Real Operating system has complete and high-level functions.
BIOS can not be used as OS practically where Real Operating systems can be used.
BIOS has a very basic User interface which is not Graphical where Real Operating System has complete and complex Graphical User Interface.
BIOS update and upgrade are harder than Real Operating system update and upgrades.

Popular BIOS Manufacturers

BIOS is manufactured by different vendors like below.

Phoenix Technologies
IBM
Dell
Gateway
BYOSOFT
American Megatrends (AMI)
Insyde Software
Award Software
General Software
Microid Research

How To Open BIOS?

As BIOS is the first software or operating system loaded into a computer at the start of the boot we have to be fast in order to open the BIOS main screen. We can make some configuration about BIOS, System Hardware, etc. BIOS manufacturers generally use function keys like F1, F2, etc to open the BIOS Configuration screen here are some of them. Also, information about the shortcut key is provided during boot.

Main BIOS Screen

Most of the BIOS software provides similar functions and screens. When we opened the BIOS screen with the F4 we will see the following screen. Main tab provides general information about the system.

System Time provides BIOS or CMOS clock of the system.
System Date provides the current date of the BIOS of the system.
Legacy Diskette A and B is used to configure Disket Drives which is abandoned.
Primary Master is the first primary disk and its size which around 42 GB.
Primary Slave is the second disk which does not exist.
Secondary Master is connected to the CD-ROM.
Secondary Slave is currently empty.
System memory is BIOS memory.
Extended Memory is RAM size which is 512 MB in this case.

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BIOS Operation Keyboard Shortcuts

After opening the BIOS we can make configuration changes and we have to save, reload or reset these changes by rebooting the system. BIOS uses function keys like below.

F1 provides help information about the BIOS.
Esc is used to exit.
Enter will select or open submenu.
F9 recover to the default settings.
F10 is used to save and exit from the BIOS setup.

Change Boot Order Configuration

One of the most used functions of a BIOS is changing the Boot Order Configuration. Generally, HDD is used to load the main operating system but in some cases like the installation of the operating system, we want to install OS from a DVD or USB. So we have to change the boot order configuration from the Boot page.

We can use +and - change the order by selecting it. When we completed the boot order configuration we can press F10 in order to save and exit with a reboot.

Exit From BIOS

We can exit from BIOS with F10 by saving the configuration but there are other alternatives provided by the Exit menu like below.

We can do the following operations and actions if we want to exit from BIOS.

Exit Saving Changes
Exit Discarding Changes
Load Setup Defaults
Discard Changes which will not exit.
Save Changes which will not exit.