UNIT 3

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Fundamental Operating Systems
The Purpose of an Operating System
 The operating system (OS) controls almost all functions on a computer.
 All computers rely on an operating system (OS) to provide the interface for interaction between
users, applications, and hardware.
 The operating system boots the computer and manages the file system.
Characteristics of Operating Systems
 The operating system has four main functions:
o Control hardware access
o Manage files and folders
o Provide user interface
o Manage applications
 Control hardware access
o The operating system manages the interaction between applications and the hardware
o OS automatically discovers and configures (Plug and Play)PnP hardware
o To communicate with the hardware, the operating system installs a device driver for
each hardware component.
o A device driver is a small program written by the hardware manufacturer
 File and folder management
o The operating system creates a file structure on the hard disk drive to allow data to be
stored
o A file is a block of related data
o Program and data files are grouped together in a directory
 User interface
 The operating system enables the user to interact with software and hardware. There are two
types of user interfaces:
o Command line interface (CLI)
o Graphical user interface (GUI)
 Application management
 The operating system locates an application and loads it into the RAM of the computer.
 Applications are software programs, such as word processors, databases, spreadsheets,games,
and many other applications.
 An application programming interface (API) is a set of guidelines used by programmers to ensure
that the application they are developing is compatible with an operating system.
 Two examples of APIs are:
o Open Graphics Library (OpenGL)
o DirectX
Operating Systems concepts
To understand the operating system, it is important to understand some basic terms.
The following terms are often used when comparing operating systems:
 Multi-user – Two or more users can work with programs and share peripheral devices, such as
printers, at the same time.

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 Multi-tasking – The computer is capable of operating multiple applications at the same time.
 Multi-processing – The computer can have two or more central processing units (CPUs) that
programs share.
 Multi-threading – A program can be broken into smaller parts that can be loaded as needed by
the operating system.
 Multi-threading allows individual programs to be multi-tasked.
Modes of Operation
 All modern CPUs can run in different modes of operation
 The mode of operation refers to the capability of the CPU and the operating environment.
 The four common modes of operation are as follows:
o Real mode
o Protected mode
o Virtual real mode
o Compatible mode
Real Mode
 Executes only one program at a time
 Addresses only 1 MB of system memory at a time
 Directly accesses memory and hardware
 Subject to crashes
 Available to all modern processors
 Only used by DOS and DOS applications
 Program Code directly controls PC hardware.
 PC hardware can be interrupted by bad code.
Protected Mode
 Has access to all memory
 Can manage multiple programs simultaneously
 Allows the system to use virtual memory
 Provides 32-bit access to memory, drivers, and I/O transfers
 Each program is assigned a space in memory
 Computer is protected from program errors
Virtual Real Mode
 Allows a real-mode application to run within a protected-mode operating system
 Creates virtual machines for each program that runs in real mode
 Each virtual machine receives 1 MB of memory and access to hardware
 In the event of a program error, only the virtual machine is affected
 OS provides virtual machine to host the code and protect the PC
Compatibility Mode
 Compatibility mode creates the environment of an earlier operating system for applications that
are not compatible with the current operating system.
Compare Operating Systems
There are two distinct types of operating systems:

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 Desktop operating systems: A desktop operating system is intended for use in a small
office/home office (SOHO) with a limited number of users.
 Network operating systems: A network operating system (NOS) is designed for a corporate
environment serving multiple users with a wide range of needs.
Desktop Operating System
o Supports a single user
o Runs single-user applications
o Shares files and folders
o Shares peripherals
o Used on a small network
 Desktop operating systems:
o Microsoft Windows: Windows XP
o Macintosh: Mac OS X
o Linux: Fedora, Ubuntu, and others
o UNIX
Network Operating Systems (NOS)
o Supports multiple users
o Runs multi-user applications
o Is robust and redundant
o Provides increased security
o Used on a network
o Provides increased security compared to desktop operating systems
 Common NOS include:
o Novell Netware
o Microsoft Windows Server
o Linux
o UNIX
Determine Proper Operating System
 To select the proper operating system:
o Create an accurate profile of our customer by analyzing the daily, weekly, and monthly
computer activities
o Select appropriate software and hardware to satisfy
What Does Our Customer Require?
 Office applications
o word processing, spreadsheets, or presentation software
 Graphics applications
o Photoshop or Illustrator
 Animation applications
o Flash
 Business applications
o accounting, contact management, sales tracking or database

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Identify Minimum Hardware Requirements
 Customer may need to upgrade or purchase additional hardware to support the required
applications and OS.
 A cost analysis will indicate if purchasing new equipment is a better idea than upgrading.
 Common hardware upgrades:
o RAM capacity
o Hard drive size
o Processor speed
o Video card memory and speed
Hardware Compatibility List (HCL)
 Most operating systems have an HCL.
 HCLs can be found on the manufacturer's website.
 HCL includes list of hardware that is known to work with the operating system.
Installing the Operating System
 Reasons to perform a clean installation of an OS:
o When a computer is passed from one employee to another

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o When the operating system is corrupted
o When a new replacement hard drive is installed in a computer
 Before performing a clean installation:
o Back up all data first
o Explain to the customer that existing data will be erased
o Confirm that all needed data has been successfully transferred
Hard Drive Setup Procedures
Operating system setup methods:
o Install an OS over a network from a server
o Install from a copy of the OS files stored on the hard drive
o Install from OS files stored on CDs or DVDs
 Partitioning and Formatting
o Hard drive must be logically divided (partitioned)
o File system must be created on the hard drive
o During the installation phase, most operating systems will automatically partition and
format the hard drive
 The following terms are used when referring to hard drive setup:
o Primary partition: This partition is usually the first partition. A primary partition cannot
be subdivided into smaller sections. There can be up to four partitions per hard drive.
o Active partition: This partition is the partition used by the operating system to boot the
computer. Only one primary partition can be marked active.
o Extended partition: This partition normally uses the remaining free space on a hard
drive or takes the place of a primary partition. There can be only one extended partition
per hard drive, and it can be subdivided into smaller sections called logical drives.
o Logical drive: This drive is a section of an extended partition that can be used to
separate information for administrative purposes.
o Formatting: This process prepares a file system in a partition for files to be stored.
o Cluster: A cluster is also called a file allocation unit. It is the smallest unit of space used
for storing data.
o Track: A track is one complete circle of data on one side of a hard drive platter. A track is
broken into groups of 512 bytes, called sectors.
o Cylinder: A cylinder is a stack of tracks lined up one on top of another to form a cylinder
shape.
o Drive mapping: Drive mapping is a letter assigned to a physical or logical drive
Prepare the Hard Drive
 The first portion of the installation process deals with formatting and partitioning the hard drive.
 The second portion prepares the disk to accept the file system.
 The file system provides the directory structure that organizes the user's operating system,
application, configuration, and data files.
 Examples of file systems:
o The FAT32 file system

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o The New Technology File System (NTFS)
Install the Operating System
 During the Windows XP installation the user must provide:
o Define currency and numerals
o Text input language
o Name of user
o Name of company
o Product key
o Computer name
o Administrator password
o Date and time settings
o Network settings
o Domain or workgroup information
Create Administrator Account
 Setup creates the administrator account with the user name “administrator”
o Change this name to keep the administrator account secure
o Only use the administrator account occasionally for critical system changes
 Create a fictitious user account to use as a template
 Use secure passwords
o These should be a minimum of 7 characters, containing at least one of each (letter,
number, and symbol)
Complete the Installation
 When Windows XP installation completes:
o Computer will reboot

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o Log in for the first time
o Register Windows XP and verify that we are using a legal copy of the OS
 Verification enables we to download patches and service packs
 Use Microsoft Update Manager to scan for new software and to:
o Install all service packs
o Install all patches
Check Device Manager for Conflicts
 Look for warning icons (yellow exclamation points)
 Double-click to learn about the problem
 Click the plus (+) sign to expand the category
 May be able to ignore an error
Custom Installation Options
 With Microsoft System Preparation
 Follow these steps for disk cloning:
o Create a master installation on one computer
o Run Sysprep
o Create a disk image of the configured computer using third-party disk-cloning software
o Copy the disk image onto a server
 When the destination computer is booted,
o A shortened version of the Windows setup program runs
o Setup configures only user-specific and computer-specific settings
o An answer file provides data normally required during set up
The Boot Sequence for Windows XP
1. Power On Self Test (POST)
2. POST for each adapter card that has a BIOS
3. BIOS reads the Master Boot Record (MBR)
4. MBR takes over control of the boot process and starts NT Loader (NTLDR)
5. NTLDR reads the BOOT.INI file to know which OS to load and where to find the OS on the boot
partition
6. NTLDR uses NTDETECT.COM to detect any installed hardware
7. NTLDR loads the NTOSKRNL.EXE file and HAL.DLL
8. NTLDR reads the registry files and loads device drivers
9. NTOSKRNL.EXE starts the WINLOGON.EXE program and displays the Windows login screen
NTLDR and the Windows Boot Menu
 If more than one OS is present on the disk, BOOT.INI gives the user a chance to select which to
use.
 Otherwise:
o NTLDR runs NTDETECT.COM to get information about installed hardware
o NTLDR then uses the path specified in the BOOT.INI to find the boot partition
o NTLDR loads two files that make up the core of XP: NTOSKRNL.EXE and HAL.DLL
o NTLDR reads the Registry files, chooses a hardware profile, and loads device drivers.

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The Windows Registry
 The Windows registry is a hierarchal database used by the Windows operating system to store
information and settings for hardware, software, users, and preferences on a system
 Recognized by distinctive names, beginning with HKEY_
 Changes to the Control Panel settings, File Associations, System Policies, or installed software
are stored in the registry
 Each user has their own section of the registry
 The Windows logon process uses the registry to set the system to the state that it was in the last
time the user logged in
 Following are the some of The Windows Registry Files
The NT Kernel
 The NT kernel, the heart of the Windows operating system, takes over. The name of this file is
ntoskrnl.exe.
Manipulating Operating System Files
 MSCONFIG: After we have installed Windows XP, we can use MSCONFIG for post-installation
modifications:
o This boot configuration utility allows we to set programs that will run at startup, and to
edit configuration files
 REGEDIT: The registry is a database that contains information and settings for all of the
hardware, software, users and preferences. REGEDIT allows users to edit the registry.
Startup Modes
 Pressing the F8 key during the boot process opens the Windows Advanced Startup Options
menu, which allows we to select how to boot Windows.
o Safe Mode – Starts Windows but only loads drivers for basic components, such as the
keyboard and display.
o Safe Mode with Networking Support – Starts Windows identically to Safe Mode and
also loads the drivers for network components.

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o Safe Mode with Command Prompt – Starts Windows and loads the command prompt
instead of the GUI interface.
o Last Known Good Configuration – Enables a user to load the configurations settings of
Windows that was used the last time that Windows successfully started. It does this by
accessing a copy of the registry that is created for this purpose.
Describing Directory Structures
 Windows file system naming conventions:
o Maximum of 255 characters may be used
o Characters such as a period (.) or a slash ( /) are not allowed
o An extension of three or four letters is added to the filename to identify the file type
o Filenames are not case sensitive
 Windows filename extension examples:
o .doc -Microsoft Word
o .txt -ASCII text only
o .jpg -graphics format
o .ppt -Microsoft PowerPoint
o .zip -compression format
 Each file has a set of attributes that control how the file may be viewed or altered.
 The following are the most common file attributes:
o R -The file is read-only
o A -The file will be archived the next backup
o S -The file is marked as a system file and a warning is given if an attempt is made to
delete or modify the file
o H -The file is hidden in the directory display
The ATTRIB Command
 we can view the filenames, extensions, and attributes by entering a DOS window (choose Start >
Run > cmd) and typing the ATTRIB command
NTFS and FAT32
 FAT32 is used where files need to be accessed by multiple versions of Windows. FAT32 is not as
secure as NTFS
 NTFS can support more and larger files than FAT32, and provides more flexible security features
for folders, files, and sizes
 Partitions can be converted from FAT32 to NTFS using the CONVERT.EXE utility, but not in the
reverse direction
Navigate a GUI (windows)
 The operating system provides a user interface that allows us to interact with the computer.
 There are two methods that we can use to navigate the file system and run applications within
an operating system:
o A GUI provides graphical representations of all the files, folders, and programs on a
computer.
o A command-line interface (CLI) is text based. we must type commands to manipulate
files and execute programs

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Manipulate Items on the Desktop
 A desktop on a computer is a graphical representation of a workspace.
 The desktop has icons, toolbars, and menus to manipulate files.
 The desktop can be customized with images, sounds, and colors to provide a more personalized
look and feel.
Desktop Properties
 To customize the GUI of our desktop, right-click the desktop and choose Properties,
 The Display Properties menu has five tabs: Themes, Desktop, Screen Saver, Appearance, and
Settings. Click any of these tabs to customize our display settings
Desktop Items
 There are several items on the desktop that can be customized, such as the taskbar and Recycle
Bin.
 To customize any item, right-click the item and then choose Properties.
The Start Menu
 On the desktop, the Start menu is accessed by clicking the Start button.
 The Start menu, displays all the applications installed in the computer, a list of recently opened
documents, and a listing of other elements, such as a search feature, help center, and system
settings.
 The Start menu can also be customized to two styles, XP and Classic
My Computer
 To access the various drives installed in the computer, double-click the My Computer icon that
appears on the desktop.
 To customize certain settings, right-click My Computer and choose Properties
 there are several settings that can be customized:
o Computer name
o Hardware settings
o Virtual memory
o Automatic updates
o Remote access
 Files can also be moved and copied using My Computer
Launching Applications
 Applications can be launched in several ways:
o Click the application on the Start menu
o Double-click the application shortcut icon on the desktop
o Double-click the application executable file in My Computer
o Launch the application from the Run window or command line
My Network Place
 To view and configure network connections, right-click the My Network Places icon.
o Connect to or disconnect from a network drive
o Right-click Properties to configure existing network connections, such as a wired or
wireless LAN connection
Explore Control Panel Applets
 Windows centralizes the settings for many features that control the behavior and appearance of
the computer. These settings are categorized in Control Panel applets

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Display Settings
 Change the resolution and color quality
 Change wallpaper, screen saver, power settings, and other options, by clicking the Advanced
button
Explore Administrative Tools
 The following sections cover some of the most common administrative utilities for
troubleshooting, managing, and maintaining Windows XP, including
o Device Manager
o Task Manager
o Event Viewer
o Remote Desktop
o Performance Settings
Device Manager
 Used to view settings for devices in the computer
 To view the system resources in the Device Manager, use the following path:
Start > Control Panel > System > Hardware > Device Manager
An exclamation mark indicates a problem with a device
Task Manager
 View all applications that are currently running
 Close any applications that have stopped responding
 Monitor the performance of the CPU and virtual memory
 View all processes that are currently running
 View information about the network connections
 To view information in the Task Manager, press Ctrl-Alt-Delete and then select Task Manager or
right-click the taskbar and select Task Manager.
Event Viewer and Remote Desktop
Event Viewer
 Logs a history of events regarding applications, security, and the system.
 These log files are a valuable troubleshooting tool.
 To access the Event Viewer, choose Administrative Tools > Event Viewer from the Control
Panel.
Remote Desktop
 Allows one computer to remotely take control of another computer.
 This troubleshooting feature is only available with Windows XP Professional.
 To access the Remote Desktop,use the following path:Start > All Programs > Accessories >
Communications > Remote Desktop Connection
Performance Settings
 To enhance the performance of the operating system, we can change some of the settings that
our computer uses, such as virtual memory configuration settings,
 To change the virtual memory setting, use the following path:Start > Control Panel > System >
Advanced > Performance area > Settings button >Advanced tab > Virtual memory section >
Change

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Install, Navigate, and Uninstall an Application
 Most applications use an automatic installation process when an application
 Microsoft recommends that users always use the Add or Remove Programs utility,when
installing or removing applications
 To open the Add or Remove Programs applet, use the following path:Start > Control Panel >
Add or Remove Programs
UPGRADING AN OPERATING SYSTEM
 Before upgrading the operating system, check the minimum requirements of the new operating
system
 Check the HCL to ensure that the hardware is compatible with the new operating system.
 Back up all data before upgrading the operating system in case there is a problem with the
installation
Upgrading the Windows XP operating system
1. Insert the Windows XP CD. Select Start > Run.
2. In the Run box, where D is the drive letter for the CDROM, type D:i386winnt32 and press Enter. The
Welcome to the Windows XP Setup Wizard displays.
3. Choose Upgrade to Windows XP and click Next. The License Agreement page displays.
4. Read the license agreement and click the button to accept this agreement.
5. Click Next. The Upgrading to the Windows XP NTFS File System page displays.
6. Follow the prompts and complete the upgrade. When the install is complete, the computer will
restart.
Preventive Maintenance technique
 Components of a preventive maintenance plan:
o Updates to the operating system and applications
o Updates to anti-virus and other protective software
o Hard drive error checking
o Hard drive backup
o Hard drive defragmentation
SCHEDULE TASKS
 Most preventive maintenance applications can be set to run automatically according to a
schedule.
 Windows has the following utilities that will launch tasks when we schedule them:
o The DOS AT command launches tasks at a specified time using the command-line
interface (choose Start > Run > cmd) and type AT /?
o The Windows Task Scheduler launches tasks at a specified time using a graphical user
interface. Start > All Programs > Accessories > System Tools > Scheduled Tasks.
System Utilities
 There are several utilities included with DOS and Windows that help maintain system integrity.
 Two system utilities that are useful tools for preventive maintenance are
o ScanDisk or CHKDSK: ScanDisk (Windows 2000) and CHKDSK (Windows XP) check the
integrity of files and folders and scan the hard disk surface for physical errors.
o Defrag: As files increase in size, some data is written to the next available space on the
disk. Defrag gathers the noncontiguous data into one place, making files run faster.

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 We can access both of these utilities by using this path: Start > All Programs > Accessories >
System Tools > Disk Defragmenter
Automatic Updates
 An automatic update service scans the system for needed updates, and recommends what
should be downloaded and installed.
 Automatic update services can setup to download and install updates as soon as they are
available or as required, and install them when the computer is next rebooted.
 The Microsoft Update Wizard is available at this path: Start > Control Panel > System >
Automatic Updates
Restore Point
 An update can sometimes cause serious problems. Perhaps an older program is in the system
that is not compatible with the current operating system
 Windows System Restore is the solution for this problem. Windows XP can create an image of
current computer settings, called a restore point.
 Then, if the computer crashes or an update causes system problems, the computer can roll back
to a previous configuration.
 To restore or create a restore point, use the following path: Start > All Programs > Accessories >
System Tools > System Restore
ERD and ASR
 Windows 2000 offers the ability to create an emergency repair disk (ERD) that saves critical
boot files and configuration information necessary to troubleshoot problems in Windows.
 Windows XP offers the same features with the Automated System Recovery(ASR) wizard.
BACKUP THE HARD DRIVE
 Backup tools allow the recovery of data.
 There are several different types of backup.
Normal Backup
 A normal backup is also called a full backup. During a normal backup, all selected files on the
disk are archived to the backup medium.
Copy Backup
 A copy backup will copy all selected files. It does not mark the files as having been archived.
Incremental Backup
 An incremental backup procedure backs up all the files and folders that have been created or
modified since either the last normal or incremental backup.
 It marks the files as having been archived by clearing the archive bit.
Differential Backup
 A differential backup backs up all the files and folders that have been created or modified since
either the last normal backup or the last incremental backup.
 The differential backup does not mark the files as having been archived.
Daily Backup
 Daily backups only back up the files that are modified on the day of the backup.
Backup Media
 There are many types of backup media available for computers:
o Tape drives are devices that are used for data backup on a network server drive. Tapes
drives are an inexpensive way to store a lot of data.

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o The Digital Audio Tape (DAT) tape standard uses 4-mm digital audiotapes to store data
in the Digital Data Storage (DSS) format.
o Digital Linear Tape (DLT) technology offers high-capacity and relatively high-speed tape
backup capabilities.
o USB flash memory can hold hundreds of times the data that a floppy disk can hold.USB
flash memory devices are available in many capacities and offer better transfer rates
than tape devices.
Troubleshooting Process
 Step 1 Gather data from the customer
 Step 2 Verify the obvious issues
 Step 3 Try quick solutions first
 Step 4 Gather data from the computer
 Step 5 Evaluate the problem and implement the solution
 Step 6 Close with the customer
1. Gather Data from the Customer
 Customer information
o Company name, contact name, address, phone number
 Computer configuration
o Operating system, patches and updates, network environment, connection type
 Use a work order to collect information
 Description of problem
o Open-ended questions
 What were we doing when the problem was identified?
o Closed-ended questions
 Are we currently logged into our network?
2. Verify the Obvious Issues
 Examine the most obvious causes of a problem.
o Is the caps lock key set to ON?
o Is there a non-bootable disk in the floppy drive?
o Are the drive settings and boot order configured correctly in BIOS?
o Can we log on as another user?
o Was the computer turned off without being shut down properly?
o Has the password changed?
o Does the monitor have power?
o Does the display have the correct settings?
3. Try Quick Solutions First
 Use the Last Known Good Configuration settings
 Enter Safe Mode to troubleshoot video problems
 Uninstall an application that was recently added
 Roll back the system using a System Restore point
 Examine the Device Manager for device conflicts
 Run cleanmgr to clean up temp files

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 Run chkdsk/f to repair problems with the hard drive
 Run defrag to speed up the hard drive
 Reboot the computer
 Login as a different user
4. Gather Data from the Computer
 Examine system files.
 Run diagnostic software.
 Refer to the computer user manual or BIOS website for the meaning of beep codes.
 Examine the event logs to determine the cause of computer problems.
5. Evaluate Problem & Implement Solution
 We may need to conduct further research
 Refer to repair manuals
 Study the product documentation
 Visit the manufacturer’s website
 Consult repair journals
 Talk to technicians who may have repaired similar problems.
 Implement the most likely solution first
 Return the computer to the original state before trying the next solution
 It may be necessary to test many potential solutions before the problem is resolved
6. Close with the Customer
 When we are confident that the problem is resolved:
 Document the customer information, problem description, and steps to resolve the issue in the
work order.
 Explain to the customer how we solved the problem .
 Let the customer verify that the problem has been solved.
 Complete all documentation including sales orders, time logs, and receipts.
 Complete the work order.
 Update the repair journal. We can use the notes from the journal for future reference.