Chapter 5: Fundamental Operating Systems

Achtung, das ist noch CISCO-IT-Essentials Version 4.0 statt 4.1

5.0 Introduction

The operating system (OS) controls almost all functions on a computer. In this chapter, you will learn about the components, functions, and terminology related to the Windows 2000 and Windows XP operating systems.

After completing this chapter, you will meet these objectives:

• Explain the purpose of an operating system.
• Describe and compare operating systems to include purpose, limitations, and compatibilities.
• Determine the operating system based on customer needs.
• Install an operating system.
• Navigate a GUI.
• Identify and apply common preventive maintenance techniques for operating systems.
• Troubleshoot operating systems.

5.1 Explain the purpose of an operating system

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. Almost all modern operating systems can support more than one user, task, or CPU.

After completing this section, you will meet these objectives:

• Describe characteristics of modern operating systems.
• Explain operating system concepts.

Roles of an Operating System
Control hardware accesss
Manage files and folders
Provide user interface
Manage applications

5.1.1 Describe characteristics of modern operating systems

Regardless of the size and complexity of the computer and the operating system, all operating systems perform the same four basic functions. Operating systems control hardware access, manage files and folders, provide a user interface, and manage applications.

Control Hardware Access

The operating system manages the interaction between applications and the hardware. To access and communicate with the hardware, the operating system installs a device driver for each hardware component. A device driver is a small program written by the hardware manufacturer and supplied with the hardware component. When the hardware device is installed, the device driver is also installed, allowing the OS to communicate with the hardware component.

The process of assigning system resources and installing drivers can be performed with Plug and Play (PnP). The PnP process was introduced in Windows 95 to simplify the installation of new hardware. All modern operating systems are PnP-compatible. With PnP, the operating system automatically detects the PnP-compatible hardware and installs the driver for that component. The operating system then configures the device and updates the registry, which is a database that contains all the information about the computer.

NOTE: The registry contains information about applications, users, hardware, network settings, and file types.

File and Folder Management

The operating system creates a file structure on the hard disk drive to allow data to be stored. A file is a block of related data that is given a single name and treated as a single unit. Program and data files are grouped together in a directory. The files and directories are organized for easy retrieval and use. Directories can be kept inside other directories. These nested directories are referred to as subdirectories. Directories are called folders in Windows operating systems, and subdirectories are called subfolders.

User Interface

The operating system enables the user to interact with software and hardware. There are two types of user interfaces:

• Command Line Interface (CLI) \x96 The user types commands at a prompt, as shown in Figure 1.
• Graphical User Interface (GUI) \x96 The user interacts with menus and icons, as shown in Figure 2.

Most operating systems, such as Windows 2000 and Windows XP, include both a GUI and a CLI.

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. The operating system ensures that each application has adequate system resources.

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. Here are two examples of APIs:

• Open Graphics Library (OpenGL) \x96 Cross-platform standard specification for multimedia graphics
• DirectX \x96 Collection of APIs related to multimedia tasks for Microsoft Windows

5.1.2 Explain operating system concepts

To understand the capabilities of an operating system, it is important to understand some basic terms. The following terms are often used when comparing operating systems:

• Multi-user \x96 Two or more users can work with programs and share peripheral devices, such as printers, at the same time.
• Multi-tasking \x96 The computer is capable of operating multiple applications at the same time.
• Multi-processing \x96 The computer can have two or more central processing units (CPUs) that programs share.
• Multi-threading \x96 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.

Almost all modern operating systems are multi-user and multi-tasking, and they support multi-processing and multi-threading.

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 mode of operation determines how the CPU will manage applications and memory. Figure 1 shows an example of the logical memory allocation.

Memory Type	Logical Memory Allocation
Conventional	0 to 640 KB
Upper	640 KB to to 1 MB
Extended	1MB to the maximum amount of RAM installed.

The four common modes of operation are real mode, protected mode, virtual real mode, and compatible mode.

Real Mode

A CPU that operates in real mode can only execute one program at a time, and it can only address 1 MB of system memory at a time. Although all modern processors have real mode available, it is only used by DOS and DOS applications or by 16-bit operating systems, such as Windows 3.x. In real mode, when an application creates an error, the entire computer can be affected because the program has direct access to memory. This can cause the computer to stop responding, restart, or shut down due to corruption of the memory space. Figure 2 is a chart of some common DOS commands that can still be used in modern operating systems, such as Windows XP.

HELP	Provides command line help
DIR	Displays the contents of a directory
ATTRIB	Changes attribute of a file to indicate a read-only, archive, system or hidden file
EDIT	Opens a file for editing
COPY	Copies a file
XCOPY	Copies files and subdirectories
FORMAT	Formats a disk
MD	Makes a new directory
RD	Removes a directory

Protected Mode

A CPU that operates in protected mode has access to all of the memory in the computer, including virtual memory. Virtual memory is hard disk space that is used to emulate RAM. Operating systems that use protected mode can manage multiple programs simultaneously. Protected mode provides 32-bit access to memory, drivers, and transfers between input and output (I/O) devices. Protected mode is used by 32-bit operating systems, such as Windows 2000 or Windows XP. In protected mode, applications are protected from using the memory reserved for another application that is currently running.

Virtual Real Mode

A CPU that operates in virtual real mode allows a real-mode application to run within a protected-mode operating system. This can be demonstrated when a DOS application runs in a 32-bit operating system, such as Windows XP.

Compatibility Mode

Compatibility mode creates the environment of an earlier operating system for applications that are not compatible with the current operating system. As an example, an application that checks the version of the operating system may be written for Windows NT and require a particular service pack. Compatibility mode can create the proper environment or version of the operating system to allow the application to run as if it is in the intended environment.

5.2 Describe and compare operating systems to include purpose, limitations, and compatibilities

A technician may be asked to choose and install an operating system for a customer. The type of OS selected depends on the customer's requirements for the computer. There are two distinct types of operating systems: desktop operating systems and network operating systems. A desktop operating system is intended for use in a small office/home office (SOHO) with a limited number of users. A network operating system (NOS) is designed for a corporate environment serving multiple users with a wide range of needs.

After completing this section, you will meet these objectives:

• Describe desktop operating systems.
• Describe network operating systems.

5.2.1 Describe desktop operating systems

A desktop OS has the following characteristics:

• Supports a single user
• Runs single-user applications
• Shares files and folders on a small network with limited security

In the current software market, the most commonly used desktop operating systems fall into three groups: Microsoft Windows, Apple Mac OS, and UNIX/Linux.

Microsoft Windows

Windows is one of the most popular operating systems today. The following products are desktop versions of the Microsoft Windows operating systems:

• Windows XP Professional \x96 Used on most computers that will connect to a Windows Server on a network
• Windows XP Home Edition \x96 Used on home computers and has very limited security
• Windows XP Media Center \x96 Used on entertainment computers for viewing movies and listening to music
• Windows XP Tablet PC Edition \x96 Used for tablet PCs
• Windows XP 64-bit Edition \x96 Used for computers with 64-bit processors
• Windows 2000 Professional \x96 Older Windows operating system that has been replaced by Windows XP Professional
• Windows Vista \x96 Newest version of Windows

Apple Mac OS

Apple computers are proprietary and use an operating system called Mac OS. Mac OS is designed to be a user-friendly GUI operating system. Current versions of Mac OS are now based on a customized version of UNIX.

UNIX/Linux

UNIX, which was introduced in the late 1960s, is one of the oldest operating systems. There are many different versions of UNIX today. One of the most recent is the extremely popular Linux. Linux was developed by Linus Torvalds in 1991, and it is designed as an open-source operating system. Open-source programs allow the source code to be distributed and changed by anyone as a free download or from developers at a much lower cost than other operating systems.

5.2.2 Describe network operating systems

A network OS has the following characteristics:

• Supports multiple users
• Runs multi-user applications
• Is robust and redundant
• Provides increased security compared to desktop operating systems

These are the most common network operating systems:

• Microsoft Windows \x96 Network operating systems offered by Microsoft are Windows 2000 Server and Windows Server 2003. Windows Server operating systems use a central database called Active Directory to manage network resources.
• Novell Netware \x96 Novell NetWare was the first OS to meet network OS requirements and enjoy widespread deployment in PC-based LANs back in the 1980s.
• Linux \x96 Linux operating systems include Red Hat, Caldera, SuSE, Debian, and Slackware.
• UNIX \x96 Various corporations offered proprietary operating systems, based on UNIX.

(Worksheet: NOS Jobs, Research NOS jobs)

5.3 Determine operating system based on customer needs

To select the proper operating system to meet the requirements of your customer, you need to understand how the customer wants to use the computer. The operating system that you recommend should be compatible with any applications that will be used and should support all hardware that is installed in the computer. If the computer will be attached to a network, the new operating system should also be compatible with other operating systems on the network.

After completing this section, you will meet these objectives:

• Identify applications and environments that are compatible with an operating system.
• Determine minimum hardware requirements and compatibility with the OS platform.

5.3.1 Identify applications and environments that are compatible with an operating system

An operating system should be compatible with all applications that are installed on a computer. Before recommending an OS to your customer, investigate the types of applications that your customer will be using. If the computer will be part of a network, the operating system must also be compatible with the operating systems of the other computers in the network. The network type determines what operating systems are compatible. Microsoft Windows networks can have multiple computers using different versions of Microsoft operating systems. These are some guidelines that will help you determine the best operating system for your customer:

• Does the computer have \x93off-the-shelf\x94 applications or customized applications that were programmed specifically for this customer? If the customer will be using a customized application, the programmer of that application will specify which operating system is compatible with it. Most off-the-shelf applications specify a list of compatible operating systems on the outside of the application package.
• Are the applications programmed for a single user or multiple users? This information will help you decide whether to recommend a desktop OS or a network OS. If the computer will be connected to a network, make sure to recommend the same OS platform that the other computers on the network use.
• Are any data files shared with other computers, such as a laptop or home computer? To ensure compatibility of file formats, recommend the same OS platform that the other data file-sharing computers use.

As an example, your customer may have a Windows network installed and wants to add more computers to the network. In this case, you should recommend a Windows OS for the new computers. If the customer does not have any existing computer equipment, the choice of available OS platforms increases. To make an OS recommendation, you will need to review budget constraints, learn how the computer will be used, and determine what types of applications will be installed.

5.3.2 Determine minimum hardware requirements and compatibility with the OS platform

Operating systems have minimum hardware requirements that must be met for the OS to install and function correctly. Figure 1 is a chart of the minimum hardware requirements for Windows 2000, Windows XP Pro, and Windows XP Home operating systems.

Minimum Hardware Requirement	Windows 2000	Windows XP Pro	Windows XP Home
CPU	Pentium 133 MHz minimum required	233 MHz minimum required (single or dual processor system) 300 MHz or higher recommended Intel Pentium/Celeron Family AMD K6/Athlon / Duron Family or compatible	233 MHz minimum required, 300 MHz or higher recommended Intel Pentium/Celeron Family AMD K6/Athlon / Duron Family or compatible
RAM	64 MB minimum required, 128 MB or higher recommended	64 MB minimum required, 128 MB or higher recommended	64 MB minimum required, 128 MB or higher recommended
Hard Disk Drive	2 GB with 650 MB of free space minimum required, 6,4 GB with 2 GB of free space recommended	1,5 GB available hard disk space minimum required, More is recommended if installing over a network.	1,5 GB available hard disk space minimum required, More is recommended if installing over a network.
Video Adapter Card	VGA resolution minimum required SVGA resolution recommended	Super VGA (600 x 800) minimum required, higher resolution recommended	Super VGA (600 x 800) minimum required, higher resolution recommended

Identify the equipment that your customer has in place. If hardware upgrades are necessary to meet the minimum requirements for an OS, conduct a cost analysis to determine the best course of action. In some cases, it may be less expensive for the customer to purchase a new computer than to upgrade the current system. In other cases, it may be cost-effective to upgrade one or more of the following components:

• RAM
• Hard disk drive
• CPU
• Video adapter card

NOTE: In some cases, the application requirements may exceed the hardware requirements of the operating system. For the application to function properly, it will be necessary to satisfy the additional requirements.

Once you have determined the minimum hardware requirements for an OS, you should ensure that all of the hardware in the computer is compatible with the operating system that you have selected for your customer.

Hardware Compatibility List

Most operating systems have a hardware compatibility list (HCL) that can be found on the manufacturer's website, as shown in Figure 2. These lists provide a detailed inventory of hardware that has been tested and is known to work with the operating system. If any of your customer\x92s existing hardware is not on the list, those components may need to be upgraded to match components on the HCL.

NOTE: An HCL may not be continuously maintained and therefore may not be a comprehensive reference.

(Worksheet: Upgrade Components, Research additional hardware components to upgrade a computer)

5.4 Install an operating system

As a technician, you may have to perform a clean installation of an operating system. Perform a clean install in the following situations:

• When a computer is passed from one employee to another
• When the operating system is corrupted
• When a new replacement hard drive is installed in a computer

After completing this section, you will meet these objectives:

• Identify hard drive setup procedures.
• Prepare the hard drive.
• Install the operating system using default settings.
• Create user accounts.
• Complete the installation.
• Describe custom installation options.
• Identify the boot sequence files and Registry files.
• Describe how to manipulate operating system files.
• Describe directory structures.

5.4.1 Identify hard drive setup procedures

The installation and initial booting of the operating system is called the operating system setup. Although it is possible to install an operating system over a network from a server or from a local hard drive, the most common installation method is with CDs and DVDs. To install an OS from a CD or DVD, first configure the BIOS setup to boot the system from the CD or DVD.

Partitioning and Formatting

Before installing an operating system on a hard drive, the hard drive must be partitioned and formatted. When a hard drive is partitioned, it is logically divided into one or more areas. When a hard drive is formatted, the partitions are prepared to hold files and applications. During the installation phase, most operating systems automatically partition and format the hard drive. A technician should understand the process relating to hard drive setup. The following terms are used when referring to hard drive setup:

• Primary partition \x96 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.
• Active partition \x96 This partition is the partition used by the operating system to boot the computer. Only one primary partition can be marked active.
• Extended partition \x96 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.
• Logical drive \x96 This drive is a section of an extended partition that can be used to separate information for administrative purposes.
• Formatting \x96 This process prepares a file system in a partition for files to be stored.
• Sector \x96 A sector contains a fixed number of bytes, generally at least 512.
• Cluster \x96 A cluster is also called a file allocation unit. It is the smallest unit of space used for storing data. It is made up of one or more sectors.
• Track \x96 A track is one complete circle of data on one side of a hard drive platter. A track is broken into groups of sectors.
• Cylinder \x96 A cylinder is a stack of tracks lined up one on top of another to form a cylinder shape.
• Drive mapping \x96 Drive mapping is a letter assigned to a physical or logical drive.

5.4.2 Prepare hard drive

A clean installation of an operating system proceeds as if the disk were brand new; there is no attempt to preserve any information that is currently on the hard drive. The first phase of the installation process entails partitioning and formatting the hard drive. This process 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.

The Windows XP operating system can use one of two file systems:

• File Allocation Table, 32-bit (FAT32) \x96 A file system that can support partition sizes up to 2 TB or 2,048 GB. The FAT32 file system is supported by Windows 9.x, Windows Me, Windows 2000, and Windows XP.
• New Technology File System (NTFS) \x96 A file system that can support partition sizes up to 16 exabytes, in theory. NTFS incorporates more file system security features and extended attributes than the FAT file system.

Figure 1 shows the steps required to partition and format a drive in Windows XP. Click the Start button in the lower right corner to see the hard drive setup steps.

(Lab: Install Windows XP, Install Windows XP using FAT32 on a 5 GB partition)

5.4.3 Install the operating system using default settings

When installing Windows XP, the installation wizard gives the option to install using typical (default) settings or custom settings. Using the typical settings increases the likelihood of a successful installation. However, the user must still provide the following information during the setup:

• Standards and formats that define currency and numerals
• Text input language
• Name of the user and company
• Product key
• Computer name
• Administrator password
• Date and time settings
• Network settings
• Domain or workgroup information

When a computer boots up with the Windows installation CD, the Windows XP installation starts with three options:

• Setup XP \x96 To run the setup and install the XP operating system, press ENTER.
• Repair XP \x96 To repair an installation, press R to open the Recovery Console.
• Quit \x96 To quit Setup without installing Windows XP, press F3.

For this section, select the Setup XP option.

5.4.4 Create accounts

An administrator account is automatically created when Windows XP is installed. The default administrator account is named "administrator". For security purposes, change this name as soon as possible. This privileged account should only be used to manage the computer\x97it should not be used as a daily account. People have accidentally made drastic changes while using the administrator account instead of a regular user account. Attackers seek out the administrative account because it is so powerful.

Create a user account when prompted during the installation process. Unlike the administrator account, user accounts can be created at any time. A user account has fewer permissions than the computer administrator. For example, users may have the right to read, but not modify, a file.

5.4.5 Complete the installation

After the Windows installation copies all of the necessary operating system files to the hard drive, the computer will reboot and prompt you to log in for the first time.

You must register Windows XP. As shown in Figure 1, you must also complete the verification that ensures that you are using a legal copy of the OS. Doing so will enable you to download patches and service packs. Performing this step requires a connection to the Internet.

Depending on the age of the media at the time of your installation, there may be updates to install. As shown in Figure 2, you can use the Microsoft Update Manager from the Start menu to scan for new software and to do the following:

• Install all service packs
• Install all patches

Start > All Programs > Accessories > System Tools > Windows Update

You should also verify that all hardware is installed correctly. As shown in Figure 3, you can use Device Manager to locate problems and to install the correct or updated drivers using the following path:

Start > Control Panel > System > Hardware > Device Manager

In Device Manager, warning icons are represented by a yellow exclamation point or a red \x93X\x94. A yellow exclamation point represents a problem with the device. To view the problem description, right-click the device and select Properties. A red \x93X\x94 represents a device that has been disabled. To enable the device, right-click the disabled device and select Enable. To open a category that is not yet expanded, click the plus (+) sign.

NOTE: When Windows detects a system error, Windows reporting displays a dialog box. If you choose to send the report, then Microsoft Windows error reporting (WER) collects information about the application and the module involved in the error and sends the information to Microsoft.

(Lab: Windows XP User Accounts and Updates, Create user accounts and check for Windows updates)

5.4.6 Describe custom installation options

Installing an operating system on a single computer takes time. Imagine the time it would take to install operating systems on multiple computers, one at a time, in a large organization. To simplify this activity, you can use the Microsoft System Preparation (Sysprep) tool to install and configure the same operating system on multiple computers. Sysprep prepares an operating system that will be used on computers with different hardware configurations. With Sysprep and a disk cloning application, technicians are able to quickly install an operating system, complete the last configuration steps for the OS setup, and install applications.

Disk Cloning

Disk cloning creates an image of a hard drive in a computer. Follow these steps for disk cloning:

1. Create a master installation on one computer. This master installation includes the operating system, software applications, and configuration settings that will be used by the other computers in the organization.
2. Run Sysprep.
3. Create a disk image of the configured computer using a third-party disk-cloning program.
4. Copy the disk image onto a server. When the destination computer is booted, a shortened version of the Windows setup program runs. The setup will create a new system security identifier (SID), install drivers for hardware, create user accounts, and configure network settings to finish the OS install.

5.4.7 Identify the boot sequence files and Registry files

You should know the process that Windows XP uses when booting. Understanding these steps can help you to troubleshoot boot problems. Figure 1 shows the boot sequence for Windows XP.

Power On Self Test (POST)

POST for each adapter card that has a BIOS

BIOS reads the MBR

MBR takes over control of the boot process and starts NTLDR

NTLDR reads the BOOT.INI file to know which OS is to load and where to find the OS on the boot partition

NTLDR uses NTDETECT.COPM to detect any installed hardware

NTLDR loads the NTOSKRLN.EXE file and HAL.DLL

NTLDR reads the registry files and loads device drivers

NTOSKRNL.EXE starts the WINLOGON.EXE program and display the Windows login screen

The Windows XP Boot Process

To begin the boot process, you first turn on the computer, which is called a cold boot. The computer performs the power-on self test (POST). Because the video adapter has not yet been initialized, any errors that occur at this point in the boot process will be reported by a series of audible tones, called beep codes.

After POST, the BIOS locates and reads the configuration settings that are stored in the CMOS. This configuration setting is the order in which devices will be tried to see if an operating system is located there. The BIOS boots the computer using the first drive that contains an operating system.

Once the drive with the operating system is located, the BIOS locates the Master Boot Record (MBR). The MBR locates the operating system boot loader. For Windows XP, the boot loader is called NT Loader (NTLDR).

NTLDR and the Windows Boot Menu

At this point NTLDR controls several installation steps. For instance, if more than one OS is present on the disk, BOOT.INI gives the user a chance to select which one to use. If there are no other operating systems, or if the user does not make a selection before the timer expires, then the following steps occur:

• NTLDR runs NTDETECT.COM to get information about installed hardware.
• NTLDR then uses the path specified in the BOOT.INI to find the boot partition.
• NTLDR loads two files that make up the core of XP: NTOSKRNL.EXE and HAL.DLL.
• NTLDR reads the Registry files, chooses a hardware profile, and loads device drivers.

The Windows Registry

The Windows Registry files are an important part of the Windows XP boot process. These files are recognized by their distinctive names, which begin with HKEY_, as shown in Figure 2, followed by the name of the portion of the operating system under their control. Every setting in Windows\x97from the background of the desktop and the color of the screen buttons to the licensing of applications\x97is stored in the Registry. When a user makes changes to the Control Panel settings, File Associations, System Policies, or installed software, the changes are stored in the Registry.

Each user has a unique section of the Registry. The Windows login process pulls system settings from the Registry to reconfigure the system to the state that it was in the last time that the user turned it on.

HKEY	DESCRIPTION
HKEY_CLASSES_ROOT	Information about which file extension map to a particular application
HKEY_CURRENT_USER	Information, such as desktop settings and history, related to the current user of PC
HKEY_USERS	Information of about all users who have logged into a system
HKEY_LOCAL_MACHINE	Information relating to the hardware and software
HKEY_CURRENT_CONFIG	Information relating to all active devices on a system

The NT Kernel

At this point, the NT kernel, the heart of the Windows operating system, takes over. The name of this file is NTOSKRNL.EXE. It starts the login file called WINLOGON.EXE and displays the XP welcome screen.

NOTE: If a SCSI drive will boot the computer, Windows will copy the NTBOOTDD.SYS file during installation. This file will not be copied if SCSI drives are not being used.

5.4.8 Describe how to manipulate operating system files

After you have installed Windows XP, you may want to make changes to the configuration. The following applications are used extensively for post-installation modifications:

• Msconfig \x96 This boot configuration utility allows you to set the programs that will run at startup and to edit configuration files. It also offers simplified control over Windows Services, as shown in Figure 1.
• Regedit \x96 This application allows you to edit the registry, as shown in Figure 2.

NOTE: REGEDT32 was used with Windows NT. In Windows XP, and Windows Server 2003, the REGEDT32 file is nothing more than a shortcut to the REGEDIT.EXE command. In Windows XP, you can enter REGEDT32.EXE or REGEDIT.EXE; both commands run the same program.

CAUTION: Using REGEDT32.EXE or REGEDIT.EXE incorrectly may cause configuration problems that could require you to reinstall the operating system.

Startup Modes

You can boot Windows in one of many different modes. Pressing the F8 key during the boot process opens the Windows Advanced Startup Options menu, which allows you to select how to boot Windows. The following startup options are commonly used:

• Safe Mode \x96 Starts Windows but only loads drivers for basic components, such as the keyboard and display.
• Safe Mode with Networking Support \x96 Starts Windows identically to Safe Mode and also loads the drivers for network components.
• Safe Mode with Command Prompt \x96 Starts Windows and loads the command prompt instead of the GUI interface.
• Last Known Good Configuration \x96 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.

NOTE: Last Known Good Configuration is not useful unless it is applied immediately after a failure occurs. If the machine is restarted and, despite its difficulties, manages to open Windows, the registry key for Last Known Good Configuration will probably be updated with the faulty information.

5.4.9 Describe directory structures

File Extensions and Attributes

In Windows, files are organized in a directory structure. The root level of the Windows partition is usually labeled drive C:\. Next, there is an initial set of standardized directories, called folders, for the operating system, applications, configuration information, and data files. Following the initial installation, users can install most applications and data in whatever directory they choose.

Files in the directory structure adhere to a Windows naming convention:

• Maximum of 255 characters may be used.
• Characters such as a period (.) or a slash (\ /) are not allowed.
• An extension of three or four letters is added to the filename to identify the file type.
• Filenames are not case sensitive.

The following filename extensions are commonly used:

• .doc \x96 Microsoft Word
• .txt \x96 ASCII text only
• .jpg \x96 Graphics format
• .ppt \x96 Microsoft PowerPoint
• .zip \x96 Compression format

The directory structure maintains a set of attributes for each file that controls how the file may be viewed or altered. These are the most common file attributes:

• R \x96 The file is read-only.
• A \x96 The file will be archived the next time that the disk is backed up.
• S \x96 The file is marked as a system file and a warning is given if an attempt is made to delete or modify the file.
• H \x96 The file is hidden in the directory display.

The filenames, extensions, and attributes can be viewed by entering a DOS window and using the ATTRIB command, as shown in Figure 1. Use the following path:

Start > Run > cmd

Navigate to the folder that contains the file that you are interested in. Type ATTRIB followed by the file name. Use a wildcard such as . to view many files at once. The attributes of each file will appear in the left column of the screen. Information about the ATTRIB command can be found at the command prompt by typing:

ATTRIB/?

The Windows equivalent of the ATTRIB command can be accessed by right-clicking a file in Windows Explorer and choosing Properties.

NOTE: To see the properties of a file in Windows Explorer, you must first set Windows Explorer to "Show Hidden Files". Use this path:

Right-click Start > Explore > Tools > Folder Options > View

NTFS and FAT32

Windows XP and Windows 2000 use FAT32 and NTFS file systems. Security is one of the most important differences between these file systems. NTFS can support more and larger files than FAT32 and provides more flexible security features for files and folders. Figures 2 and 3 shows the file permission properties for FAT32 and NTFS.

Partitions can be converted from FAT32 to NTFS using the CONVERT.EXE utility. Doing this will provide the extra security advantages of NTFS. To restore an NTFS partition back to a FAT32 partition, reformat the partition and restore the data from a backup.

CAUTION: Before converting a file system, remember to back up the data.

(Worksheet: FAT32 and NTFS, Answer NTFS and FAT32 questions)

5.5 Navigate a GUI (Windows)

The operating system provides a user interface that allows you to interact with the computer. There are two methods that you can use to navigate the file system and run applications within an operating system:

• A Graphical User Interface (GUI) provides graphical representations (icons) of all of the files, folders, and programs on a computer. You manipulate these icons using a pointer that is controlled with a mouse or similar device. The pointer allows you to move icons by dragging and dropping, and execute programs by clicking.
• A Command Line Interface (CLI) is text-based. You must type commands to manipulate files and execute programs.

After completing this section, you will meet these objectives:

• Manipulate items on the desktop.
• Explore Control Panel applets.
• Explore administrative tools.
• Install, navigate, and uninstall an application.
• Describe upgrading operating systems.

## * Set ALLOWTOPICVIEW = KlausKellermann

• • Set ALLOWTOPICCHANGE = KlausKellermann

-- KlausKellermann - 13 Sep 2010