What happens when you turn on your PC? Lights come on the keyboard and monitor, the computer's brand logo may appear on the screen, then the operating system loading message appears. This is all occurring on screen, but in the background, your computer is actually powering on and preparing its external and internal parts. Many assume the Operating System (OS) is the first program a computer loads and operates on but the actual start-up program is the BIOS. BIOS stands for Basic Input/Output System, which is inbuilt in every PC during manufacturing and is loaded, run and executed when you press the power ON button of your PC. The BIOS is a sort of firmware interface for a computer. Different components, such as pen drives, graphics card, keyboard and mouse and disc drives attached to a computer, need to be initialized and identified to the computer. The BIOS does this in the form of a check-list ("turn USB ports on", done) and this procedure is known as POST (power-on self-test). The operating system itself is a program, which needs to be loaded and executed. This too is performed by the BIOS, which locates the OS program on the computer's hard disk and runs the program. One needs to enter the BIOS interface to change various system-level settings, such as changing the system clock, changing the boot up drive and managing memory. Listed below are the steps on how to access the computer's BIOS setup. How to Get Into Your Computer's BIOS? Step 1: Start your PC or restart it. When the computer starts up, usually the manufacturer's logo or the brand name of the PC is displayed on a black screen. In some cases, the screen turns into the logo of the operating system and a "loading" or "starting" message appears on the screen. At such booting screens, a small message is displayed, which has the combination of access keys needed to enter the BIOS. Examples of such messages are:

• Press "key" to enter BIOS
• "key" = Setup
• To enter the BIOS setup, press "key" + "key"
• Press "key" to access system configuration
• Press "key" to enter the Setup menu

In some computers, the manufacturer's logo or brand name shows up and no message for entering the browser occurs. So try pressing the Tab or the Esc key to remove it. You can either note the key down or if the screen changes too fast for you to enter the BIOS, press the Pause/Break key on your keyboard. This key will pause the booting screen, so you can understand which keys are needed to access the BIOS. To unpause such a screen, press any key. Step 2: Once you know the access key combinations, then press that key or press the combination of keys during the booting screen to enter the BIOS interface. In some computers, just one press of the key is enough, with others, you may need to tap it repeatedly. Do not press and hold down the key with force or press it too many times. The system may hang or an error code will show up on screen and you will need to restart your PC. With certain machines, pressing the DEL key repeatedly at the boot up screen, before the OS loading screen appears, can bring up the BIOS screen. Other common BIOS keys are F1, F2, F10, F12 and ESC. Step 3: The BIOS is not dependent in any way on the operating system. So whether you are running Windows 7 or Mac OS X, the OS has nothing to do with your BIOS and hence different operating systems does not mean different BIOS access keys. Instead, your computer's BIOS depends on the manufacturer of the motherboard, like Acer or ASUS. So there are proprietary access keys to enter the BIOS screen, based on the brand of the computer. Some computer systems and their BIOS access shortcuts are:

Manufacturer	Access Keys
Acer	F1, F2, CTRL+ALT+ESC
Compaq	F10 (newer), F1, F2, DEL (older models)
Dell 400	F3, F1
Dell 4400	F12
Dell Inspiron	F2
Dell Latitude	Fn+F1, Fn+ESC
Gateway 2000	F1
Hewlett-Packard (HP)	F1, F2, ESC (for laptops)
IBM	F1, F2 (E-pro laptop)
Micron	F1, F2, DEL
Packard Bell	F1, F2, DEL
Sharp	F2
Sony VAIO	F2
Toshiba 335CDS	ESC
Toshiba Portégé	ESC
Toshiba Satellite	F1
Toshiba Tecra	F1 or ESC

Warning: The above-mentioned access keys may differ from computer to computer, so always verify the information prior to usage. The correct access keys are provided as a part of the computer's documentation. This site does not assume any responsibility for any issues that could occur by using the above information. The BIOS is a rather sensitive part of your computer's internal makeup, so pressing a lot of keys at the boot up screen is not a good idea, unless you know what you are doing. So do not press any or all keys in tandem or with force to enter your computer's BIOS. Instead, refer to your computer's manual and look for System Settings or similar headings to find the correct BIOS key. You can even search online using your computer's model number and make. Once you have actually accessed the BIOS and are facing the lovely light blue screen, here's a word of caution; fiddling with BIOS settings is not for novices or the ill-informed. If you know what you are doing, then only change settings and to be safe, write down what you are changing, in case you need to go back and re-change it. Use the arrow keys and function keys to navigate and select options within the menu. Accessing the BIOS of a computer's system can be done to change certain basic computer settings and workings, but should be carried out with caution.