Operating System

An operating system (sometimes abbreviated as "OS") is the program that, after being initially loaded into the computer by a boot program, manages all the other programs in a computer. An Operating System is basically a set of programs that provide control of the CPU (Central Processor Unit) and its resources. Any general-purpose computer, such as a PC or a Mac to mention the most well known, requires an Operating System (OS) to organize the various hardware and software components that make up the system.

The operating system is the core software component of our computer. It performs many functions and is, in very basic terms, an interface between your computer and the outside world. Hardware, a computer is described as consisting of several component parts including our monitor, keyboard, mouse, and other parts. The operating system provides an interface to these parts using what is referred to as "drivers". This is why sometimes when you install a new printer or other piece of hardware, your system will ask you to install more software called a driver.

A driver is a specially written program which understands the operation of the device it interfaces to, such as a printer, video card, sound card or CD ROM drive. It translates commands from the operating system or user into commands understood by the the component computer part it interfaces with. It also translates responses from the component computer part back to responses that can be understood by the operating system, application program, or user. The below diagram gives a graphical depiction of the interfaces between the operating system and the computer component.

An operating system performs these services for applications:

• In a multitasking operating system where multiple programs can be running at the same time, the operating system determines which applications should run in what order and how much time should be allowed for each application before giving another application a turn.
• It manages the sharing of internal memory among multiple applications.
• It handles input and output to and from attached hardware devices, such as hard disks, printers, and dial-up ports.
• It sends messages to each application or interactive user (or to a system operator) about the status of operation and any errors that may have occurred.
• It can offload the management of what are called batch jobs (for example, printing) so that the initiating application is freed from this work.
• On computers that can provide parallel processing, an operating system can manage how to divide the program so that it runs on more than one processor at a time.

Core task of Operating System

It must be pointed out that most operating systems also contain other utilities and auxiliary functions that do not make up the OS, but are only additions to it. Although some amy argue that an OS has several tasks that include what others would consider as utilities and auxiliaries, the core tasks of an operating system fall into the following six categories:

·         Processor management - controls processes and applications access of CPU so that each has its fair share.

·         Memory management - controls the different types of memories to allot space to applications.

·         Device management - controls devices, mainly through their drivers.

·         Storage management - manages the file storage facilities.

·         Application interface - application program interfaces (APIs) are to software what drivers are to hardware.

·         User interface - This is what you are most familiar with, how the user communicates with the computer.

 

Other Operating System Functions

The operating system provides for several other functions including:

• System tools (programs) used to monitor computer performance, debug problems, or maintain parts of the system.
• A set of libraries or functions which programs may use to perform specific tasks especially relating to interfacing with computer system components.

The operating system makes these interfacing functions along with its other functions operate smoothly and these functions are mostly transparent to the user.

Operating System Types

There are many types of operating systems. The most common is the Microsoft suite of operating systems. They include from most recent to the oldest:

• Windows XP Professional Edition - A version used by many businesses on workstations. It has the ability to become a member of a corporate domain.
• Windows XP Home Edition - A lower cost version of Windows XP which is for home use only and should not be used at a business.
• Windows 2000 - A better version of the Windows NT operating system which works well both at home and as a workstation at a business. It includes technologies which allow hardware to be automatically detected and other enhancements over Windows NT.
• Windows ME - A upgraded version from windows 98 but it has been historically plagued with programming errors which may be frustrating for home users.
• Windows 98 - This was produced in two main versions. The first Windows 98 version was plagued with programming errors but the Windows 98 Second Edition which came out later was much better with many errors resolved.
• Windows NT - A version of Windows made specifically for businesses offering better control over workstation capabilities to help network administrators.
• Windows 95 - The first version of Windows after the older Windows 3.x versions offering a better interface and better library functions for programs.

There are other worthwhile types of operating systems not made by Microsoft. The greatest problem with these operating systems lies in the fact that not as many application programs are written for them. However if you can get the type of application programs you are looking for, one of the systems listed below may be a good choice.

• Unix - A system that has been around for many years and it is very stable. It is primary used to be a server rather than a workstation and should not be used by anyone who does not understand the system. It can be difficult to learn. Unix must normally run an a computer made by the same company that produces the software.
• Linux - Linux is similar to Unix in operation but it is free. It also should not be used by anyone who does not understand the system and can be difficult to learn.
• Apple Macintosh - Most recent versions are based on Unix but it has a good graphical interface so it is both stable (does not crash often or have as many software problems as other systems may have) and easy to learn. One drawback to this system is that it can only be run on Apple produced hardware.

Performing a new install: Pre-installation steps

To perform a new install of Windows XP:

1.      Insert your XP CD in the drive. It should automatically launch the Setup routine. If it doesn't, click Start -> Run, type d:\setup.exe (where d: is the letter of your CD drive) in the Open box and click OK.

2.      You'll be presented with a menu of choices. Click Install Windows.

3.      The first setup screen asks you what type of installation to perform. Select New Installation (Advanced) from the drop-down list and click the Next button to move to the next screen.

4.      Read through the licence agreement and, if you accept it, click I Accept This Agreement, then click Next.

5.      Type in your Windows Product Key, which you'll find on the CD cover, then click Next.

6.      The next screen lets you choose from a variety of options. If you'd like to copy all the installation files to your hard drive (which increases the speed of the installation and makes it easy to reinstall at a later point, but will chew up some 500 megabytes of hard disk space) or you'd like to choose the drive and partition where XP is installed (which you must do if you intend to dual boot, otherwise you'll trash the existing installation), click the Advanced Options button. If you are visually disabled, click the Accessibility Options button and you will be able to use the Windows Magnifier and/or the Windows Narrator during setup. The Magnifier lets you magnify portions of the screen; the Narrator reads each screen during setup. Click Next when you're ready to proceed.

7.      The next screen lets you choose which file system to use. XP runs on NTFS (NT File System), FAT (File Allocation Table) or FAT32 (FAT 32-bit version). If you pick FAT, Setup automatically uses FAT32 for partitions larger than 2G.