A+ Guide to Managing and Maintaining your PC, 6e€¦ · · 2008-09-04A+ Guide to Managing and...

A+ Guide to Managing and

Maintaining your PC, 6e

Chapter 2

Introducing Operating Systems

A+ Guide to Managing and Maintaining your PC, 6e 2

Objectives

• Learn about the various operating systems and the

differences between them

• Learn how an OS interfaces with users, files and

folders, applications, and hardware

• Learn about a few OS tools you can use to examine

and maintain a system


Introduction

• A computer comprises hardware and software

– Physical devices are the visible component

– The controlling software component is not visible

• Computer technicians need to master both parts

• Chapter 1 provided an overview of hardware devices

• Chapter 2 introduces critical system software


Operating Systems Past and Present

• What an operating system (OS) does:

– Manages hardware

– Runs applications

– Provides an interface for users

– Retrieves and manipulates files

• The OS can be analogized to a “middleman”

• A computer needs only one operating system

• Operating systems have evolved to a complex form


Figure 2-1 Users and applications depend on the OS

to relate to all applications and hardware components


DOS (Disk Operating System)

• The first OS used by IBM computers/compatibles

• Where DOS can still be found:

– Specialized systems using older applications

– On troubleshooting disks or CDs

• Windows 3.x and DOS

– Windows 3.x provided a graphical interface

– Underlying OS functions were performed by DOS

• Windows 9x/Me uses DOS in the underlying OS

• Windows XP/2000 run DOS emulation programs


Figure 2-3 Windows 3.x was layered between DOS

and the user and applications to provide a graphics

interface for the user and a multitasking

environment for applications


Windows 9x/Me

• Refers to Windows 95, Windows 98, Windows Me

• Combine a DOS core with graphical user interface

• Designed to bridge legacy and newer technologies

– Backward-compatible with older systems

– Able to accommodate new technologies

• Cautionary note on minimum requirements

– May differ for upgrades and new installations

– May differ for installation and run-time operation


Figure 2-5 Windows 9x/Me is the bridge from DOS to Windows NT


Windows NT

• Two versions of Windows NT (New Technology):

– Windows NT Workstation for desktops

– Windows NT Server to control a network

• Best known feature: new OS core replacing DOS

• Avoid installing Windows NT

– Windows NT introduced many new problems

– Problems only solved in later versions of Windows


Windows 2000

• Upgrades Windows NT (both desktop and server)

• Improvements over Windows NT:

– A more stable environment

– Support for Plug and Play

– Device Manager, Recovery Console, Active Directory

– Better network support

– Features specifically targeting notebook computers

• OS includes only qualified hardware and software

• Windows 2000 is being phased out


Windows XP

• Integrates Windows 9x/Me and Windows 2000

• Two main versions: Home Edition and Professional

• Noteworthy new features:

– Allows two users to logon and open applications

– Incorporates Windows Messenger and Media Player

– Adds advanced security, such as Windows Firewall

• Hardware requirements

– 64 MB RAM (128 MB recommended)

– 1.5 GB free hard drive space (2 GB recommended)

– 233-MHz CPU speed (300-MHz recommended)


Figure 2-8 The Windows XP desktop and Start menu


Windows Vista

• Next generation of Windows operating systems

• Code-named Longhorn

• Noteworthy new features:

– New graphical interface

– Revamped engine

– A new interface between it and applications

• Scheduled release dates:

– November 2006 for business editions

– January 2007 for consumer editions


Windows Server 2003

• Refers to a suite of Microsoft operating systems:

– Windows Small Business Server 2003

– Storage Server 2003

– Server 2003 Web Edition

– Server 2003 Standard Edition

– Server 2003 Enterprise Edition

– Server 2003 Datacenter Edition

• Not designed for use in a PC

• Not covered in this text


UNIX

• Comprises a class of operating systems

• UNIX versions referred to as flavors or distributions

• Chief uses:

– Controlling networks

– Supporting Internet-based applications


Linux

• Variation on UNIX created by Linus Torvalds

• OS kernel and source code are freely distributed

• Popular distributions:

– SuSE (www.novell.com/linux/suse)

– RedHat (www.redhat.com)

– TurboLinux (www.turbolinux.com)

• Used as both a server and a desktop

• X Windows: GUI shells for UNIX and Linux

http://www.novell.com/linux/suse

http://www.redhat.com/

http://www.turbolinux.com/


OS/2

• Jointly developed by IBM and Microsoft

• Chiefly used in certain types of networks

• Part of OS/2 was incorporated into Windows NT

• OS/2 is not covered in this book


Mac OS

• First introduced in 1984 with Macintosh computers

• Current version: Mac OS X (ten)

• Mac OS X can work on some Intel-based computers

• Markets: education, desktop publishing, graphics

• Noteworthy features:

– Support for graphics and multimedia capabilities

– Use of the Finder program to provide the desktop

– Superior Plug and Play capabilities

– Excellent support for multitasking


Figure 2-10 The Mac OS X desktop is intuitive and easy to use


What an Operating System Does

• Four functions common to all operating systems:

– Providing a user interface

– Managing files

– Managing applications

– Managing hardware

• All OSs also have similar core components


Operating System Components

• Components common to all OSs: shell and kernel

• The shell exposes functions to users and applications

– Example 1: enables user to select a CD

– Example 2: enables application to print a document

• The kernel (core) interacts with hardware devices

– Example: passes a print request to a printer device

• Registry database and initialization files

– Used to store configuration information in Windows


Figure 2-11 Inside an operating system, different

components perform various functions


An OS Provides a User Interface

• Sequence of events occurring after PC is turned on

– The operating system is loaded

– Running OS provides an interface (desktop)

– OS awaits an event, such as a double-click

• A user can initiate an event in several ways:

– Click a menu item

– Enter a command in Run dialog or command console

– Double-click an icon


Figure 2-12 Enter command lines in a Command Prompt window


Figure 2-13 A menu-driven interface: Windows Explorer in Windows XP


An OS Manages Files and Folders

• File system: organizes files and folders

• File systems used by Windows for hard drives:

– File Allocation Table (FAT): tracks disk space usage

– New Technology File System (NTFS): replacing FAT

• Organization of a hard drive or floppy disk

– Platter contains concentric tracks

– Track contains 512 byte sectors

– Cluster contains one or more sectors

– Cluster is the smallest unit on disk for storing a file


Figure 2-14 A hard drive or floppy disk is divided into tracks

and sectors; several sectors make one cluster


Files and Directories

• File system hierarchy:

– Directories (called folders in Windows)

– Subdirectories (child directories)

– Files

• Directories can contain subdirectories and files

• Directory table: lists subdirectories and files

• Root directory: directory for a logical drive; e.g., C:\

• Path: drive, directories, filename, and file extension

– Example: C:\wp\data\myfile.txt points to “myfile”


Figure 2-15 A hard drive is organized into directories and

subdirectories that contain files


Partitions and Logical Drives on a

Hard Drive

• Hard drives are organized into partitions

• Two types of partitions

– Primary: can only have one logical drive; e.g., C:\

– Extended: can have one or more logical drives

• Logical drive (sometimes called a volume)

– Formatted using a file system

– Has a root directory and subdirectories

• Disk Management tool

– Used to create/view partitions, format logical drives


Figure 2-18 Use the Windows 2000/XP Disk Management

utility to see how a hard drive is partitioned


An OS Manages Applications

• The OS installs and runs all other PC software

• Application: software providing services for users

• Applications rely on the OS for support operations

– Example: MS word relies on OS to manage memory

• Applications are typically tailored to a single OS

– Ensure that OS is suitable for a given application


Installing Application Software

• Sources of application software:

– Internet, CDs, DVDs, or floppy disks

• Installation program is provided by application

• Tasks performed by installation program:

– Folders are created on the hard drive

– Files are copied to the folders

– For Windows, entries are made in Windows registry

– Icons are usually placed on desktop

– For Windows, entries are added to the Start menu


Launching Application Software Using

the Windows Desktop

• An application has to be started before use

– You run, load, launch, or execute the application

• Four ways to run software:

– Use a shortcut icon

– Use the Start menu

– Use the Run command

– Use Windows Explorer or My Computer


Real (16-bit), Protected (32-bit), and

Long (64-bit) Operating Modes

• Bit type: number of bits simultaneously processed

• Real (16-bit) mode

– Exposes hardware to application (no longer used)

– Example: DOS

• Protected (32-bit) and Long (64-bit) modes

– OS controls how an application accesses hardware

– Preemptive multitasking is supported

– Example: Windows XP Professional x64 Edition

• Multiprocessing involves multiple CPUs


16-bit, 32-bit, and 64-bit Software

• 16-bit software

– Written for Windows 3.x

– Data access is 16 bits at a time

• 32-bit programs

– Written for Windows NT/2000/XP and Windows 9x/Me

• 64-bit programs

– Written for Windows XP Professional x64 Edition

• Most software today is 32-bit or 64-bit


An OS Manages Hardware

• OS interacts with hardware using drivers or BIOS

• Software falls into three categories:

– Device drivers or the BIOS

– Operating system

– Application software


Figure 2-23 An OS relates to hardware by way of BIOS and

device drivers


How an OS Uses Device Drivers to

Manage Devices

• Device drivers: specify how to interact with a device

– Example: a driver links a computer to a digital camera

• Drivers are provided by OS and device manufacturer

• Three kinds of drivers (corresponds to a mode)

– 16-bit real, 32-bit protected, and 64-bit long

• Device drivers in Windows

– Before installation, verify Microsoft has tested device

– Registry stores information about 32-bit device drivers

– Updated drivers are available at manufacturer’s site


How an OS Uses System BIOS to

Manage Devices

• System BIOS contains device information

– Instructions enable CPU to communicate with device

– Example: keyboard activated at startup using BIOS

• Configure BIOS device interaction in CMOS setup

• The OS may use system BIOS to access devices

• Disadvantage of using BIOS device management

– BIOS does not operate as fast as device drivers


How an OS Manages Memory

• Memory functions performed by OS at startup

– Launches utilities to manage memory

– Assigns addresses to each location of memory

• Drivers, OS, and application use memory addresses

– Enables three software layers to refer to shared data

• 16-bit program in real mode has direct access to RAM

• The OS controls memory access in protected mode

– The address spaces of a program is protected

– Virtual memory expands number of running programs


Figure 2-27 Protected mode allows more than one

program to run, each protected from the other by

the operating system


OS Tools to Examine a System

• A variety of tools are available:

– The Windows Desktop

– My Computer and Windows Explorer

– System Properties

– Control Panel

– Device Manager

– System Information

– Windows Help and the Microsoft Web Site


The Windows Desktop

• Primary tool provided by the Windows shell

• Terms associated with the desktop

– Taskbar: displays information, offers program access

– Service: support program running in the background

– System tray: displays icons for running services

– Shortcut: desktop icon pointing to a program

• Tools used to configure the desktop

– Display Properties Window

– The Taskbar and System Tray

– Shortcuts


Figure 2-28 The Windows XP desktop and Start menu


My Computer and Windows Explorer

• Used to manage files, folders, and other resources

• Tools share similar functionality

• Perform a wide range of tasks using shortcut menus

– Example: create a new file

• File and folder operations performed with Explorer

– Creating a folder

– Deleting a folder

– Changing file attributes

– Changing folder options


Figure 2-41 Create a new file using Windows Explorer


System Properties

• Two ways to open utility:

– Right-click My Computer and select Properties

– Click the System applet in the Control Panel

• Some tasks that can be performed

– View processor and memory information

– Change the name of the computer on the network

– Access Device Manager on the Hardware tab

– Control performance on the Advanced tab

– Switch System Restore on or off

– Use the Automatic Update tab to control updating


Control Panel

• Contains applets used to manage the system

• Accessing Control Panel in Windows XP

– Click Start and the click Control Panel

• Two views: Category View and Classic View

• Applets can be launched via the Run dialog box

– Example: enter Main.cpl to open Mouse Properties


Device Manager

• Primary graphical tool for solving hardware problems

• Primary screen displays a list of devices

– Right click Properties to view device details

• Some tasks that can be performed

– Enable, disable, uninstall a device

– Update device drivers

– Uninstall device drivers

• Symbols are used to indicate a device status

– Example: red X over device indicates it is disabled


Figure 2-47 Windows XP Device Manager gives

information about devices and allows you to uninstall a

device


System Information

• Used to view detailed information about the system

• Important features

– BIOS version you are using

– The directory where the OS is installed

– How system resources are used

– Information about drivers and their status

• To open utility, enter Msinfo32.exe in Run dialog box


Windows Help and the Microsoft Web

Site

• Key guide to system

• Excellent troubleshooting resource

– Example: analyze problem with Internet connection

• Microsoft Web site: http://support.microsoft.com

• Use search engine to locate alternative resources

– Ensure that the alternative site is reputable

http://support.microsoft.com/


Figure 2-51 Troubleshooter making a suggestion to

resolve a problem with using the modem to connect

to the Internet


Keystroke Shortcuts in the OS

• Simplify interaction with the operating system

• Examples

– Function keys: F4, F5, F8

– Text editing operations: Ctrl+C, Ctrl+V, Ctrl+x

• Shortcut keys are critical when mouse is not working


Summary

• The OS manages system resources for users and

applications

• DOS (disk operating system): early command-

driven OS

• Modern OSs: Windows 2000/XP, Linux, Mac OS X

• Operating systems are divided into a kernel and

user shell

• Two OS running modes: real and protected


Summary (continued)

• OS functions: providing a user interface, managing

files, managing applications, and managing hardware

• Windows desktop: primary graphical interface to OS

• Windows Explorer: used to navigate directory and

manipulate files and folders

• Other tools: System Properties, Control Panel, Device

Manager, System Information, and Windows Help

• Keystroke shortcuts provide a way to perform tasks

without a mouse

A+ Guide to Managing and Maintaining your PC, 6e€¦ · · 2008-09-04A+ Guide to Managing and...

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