Computer Booting Process, Essay Example

Booting of the computer means the procedure of powering it on and then starting its operating system. It can also be defined as a process of bootstrapping that starts the operating system of the computer when its power is turned on. Boot sequence is the initial set that is performed by the computer when its power is turned on. The boot loader loads for the computer the main operating system. The computer and the monitor are turned on and the booting process starts. If no image is seen, then one should ensure that the monitor and computer cables are plugged in and turned on. Normally, the computer usually beeps once or twice on booting up. If it beeps repeatedly with no display then something is wrong with it. Otherwise, it will go on and perform a power on self test. In this power self test, the keyboard flash its lights, CDROM and floppy lights turn on, and some sound of hard drives and floppy are heard as they spin. A typical system of the computer boots over and over again without problems starting the operating system (OS) of the computer and identifying its software and hardware components that work together in providing the user with computing experience. What are the processes that happen between the times it is powered on and when GUI (Graphical User Interface) icons appear on its desktop?

For a computer to boot successfully, its operating system, hardware components and BIOS (Basic Input/output System) must all be working properly. If in any case one of them is not working properly then booting sequence is likely to fail. When the computer’s power is turned on, the CPU (central processing unit) initializes itself; this is triggered by a series of the clock ticks that are generated by the clock system. One function of this CPU’s initialization is looking for the system’s ROM BIOS for its first instruction in the starting up program.

The first instruction is stored by the ROM BIOS; this instruction runs the Power on Self Test (POST) in a memory address that is predetermined. The POST starts with checking the BIOS chip and then tests the CMOS RAM. If no battery failure is detected by the POST, then it continues to initialize the CPU. It checks all the inventoried hardware devices like video card, all the secondary storage devices like the floppy drives and hard drives, the ports and the other hardware devices like the mouse and the keyboard so as to ensure they are properly functioning. The POST is usually followed by one or even two screens of the information about the hardware: the hard drives sizes and extra cards that may be on the computer system. When all the components are checked to be functioning properly by the POST and the CPU has initialized successfully, then the BIOS looks for an OS to load it.

Basically the BIOS look for the CMOS (Complementary Metal Oxide Semiconductor) chip so as to inform it on where to look for the OS. In most personal computers, the OS loads from the drive C on the hard drive although it has capability of loading it from the CD, floppy disk or ZIP drive. The CMOS has certain order in which it looks for the OS; this process of locating for the OS is called boot sequence although it can be changed by altering the setup of the CMOS. In looking for the appropriate boot drive, the BIOS first encounters the boot record which informs it of where the OS beginning is and the following program file that initializes the OS.

After the initialization of the OS, BIOS copies its files into the memory and subsequently the OS takes over the booting process. When OS takes the control, it performs another system’s memory inventory and the availability of the memory although checked earlier by the BIOS. It loads the device drives it needs to control the peripheral devices like the scanner, printer, mouse, optical drive and the keyboard. This is usually the final stage in the process of booting.

The machine provides a list of user accounts and this will depend on whether they have been created or not. If they have been created, then a list of user names and the passwords are shown on the monitor screen. When the user names and password (although not seen on the screen) are typed and entered, then the computer logs in and the desktop is shown. Otherwise, if the desktop is not shown, then something may be wrong with the computer. If nothing wrong, then one can go on and start using the computer.

That is a simple booting process explanation which a computer goes through when it is booting. It takes very few minutes or even seconds depending on the type of the computer being used.