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Week 6-7

Understanding and Supporting Windows NT Workstation

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You Will Learn…

About the Windows NT environment and its architectureAbout the strengths and weaknesses of Windows NTHow to evaluate when Windows NT is the best choice a PC OSHow to install and customize Windows NT

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You Will Learn…

How to set up a Windows NT environment for a DOS or Windows 3.x applicationHow to use some Windows NT troubleshooting techniques and tools

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Windows NT vs. Windows 9x

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Features of Windows NT

Desktop performanceHardware profilesInternet ExplorerPeer Web ServicesSecurityOS stability

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Not All Hardware Devices Are Supported by Windows NT

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The Windows NT Desktop13

The Windows NT Command Prompt

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The Windows NT Command Prompt

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Choosing Between Windows 9x and Windows NTDoes Windows NT support all the hardware devices on your PC?Is the PC powerful and big enough to support Windows NT?Will the software you intend to use on the PC work better under Windows 98 or Windows NT?Is price a factor?

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Upgrading from Windows 9x to Windows NT

No automatic upgrade pathNo transfer of system settingsRequires reinstallation of each application

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A Choice of File Systems

FAT16 file systemWindows NT file systemNT does not support FAT32

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FAT16 File System

Used by Windows 9x and its predecessorsTo manage data on a logical drive, uses:• Boot record• FAT • Directories• Data files

Advantages of FAT16 over NTFS • Less overhead• Compatible with other operating systems• Can boot PC from a disk to gain access to drive

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Windows NT File System

Works only with Windows NTUses a database called the master file table (MFT) as its core componentAdvantages of NTFS over FAT16• Recoverable• Increased security• Supports mirroring drives• Uses smaller cluster sizes• Supports large-volume drives

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Master File Table13

Hard Drive Partitions

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The Dual Boot

The ability to boot from either Windows NT or another OSSystem partition must be FAT rather than NTFS

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Windows NT Environment and Architecture

Goals of Windows NT• Room to grow• Portability to different platforms• Compatibility with other OSs and legacy

software• Security• Performance and reliability

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The Modular Concept of Windows NT

Isolate one process from another so that a change in one process has the least possible effect on other processes

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DOS Analogy

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Windows 9x OS Analogy

Most analogous to Windows 9x OS13

Windows NT OS Analogy

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Core Components of Windows NT ArchitectureUser mode• Nonprivileged processor mode• Programs have only limited access to

system information and can only access hardware through other OS services

Kernel mode• Privileged processor mode• Programs have extensive access to

system information and hardware

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User Mode and Kernel Mode

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User Mode

Divided into different modules called subsystems• Environment subsystems• Integral subsystems

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How Programs Interact with Subsystems

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Kernel Mode

Combination of hardware abstraction layer (HAL) and executive services

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Executive Services Portion of Kernel Mode

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Windows NT Memory Model13

Processes and Threads

Process• A program or group of programs that is running,

together with the system resources assigned to it, such as memory addresses, environmental variables, and other resources

Thread• A single task that the process requests from the

kernel, such as the task of printing a file

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Virtual DOS Machine

Isolates an application from the rest of the system by providing the entire DOS-like environment to the applicationComponents of a NTVDM• Ntvdm.exe• Ntio.sys• Ntdos.sys• An instruction execution unit

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Windows NT Networking

Workgroup• Logical group of computers and users that share

resources• Control of administration, resources, and security

is distributed throughout the networkDomain• A group of networked computers that share a

centralized directory database of user account information and security for the entire set of computers

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A Windows NT Workgroup13

A Windows NT Domain

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Primary Domain Controller (PDC)

User accountsGroup accountsComputer accounts

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User Accounts

Control who has access to what programs, files, and other resourcesAre stored in the SAM database that defines the NT user, including username, password, memberships, and rights

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Creating a User Account13

Creating a User Account

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Creating a User Account13

Creating a User Account

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Creating a User Account13

Creating a User Account

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Installing and Customizing Windows NT

Preparing for the installationStep-by-step installation

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Preparing for the Installation

Preparing for Windows NT• Determine if hardware can support

Windows NT by searching the HCL or using the NT Hardware Qualifier (NTHQ)

Choosing the right file system (FAT16 vs. NTFS)

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What Happens During the Boot Sequence

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What Happens During the Boot Sequence

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Files Needed to Successfully Boot Windows NT

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Troubleshooting the Boot ProcessLast Known Good Configuration• Copy of hardware configuration saved from the

RegistryWindows NT boot disks (3)Windows NT emergency repair disk (ERD)• Contains information unique to the OS and hard

drive (a backup of the Windows NT Registry on the hard drive)

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Using the Boots Disks and ERD to Recover from a Failed Boot

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Why Applications Might Not Work with Windows NTDOS applications that try to access hardware directly are shut down by Windows NTA 16-bit Windows application that uses virtual device drivers (VxD) will fail because these drivers attempt to access hardware directlyA 32-bit application developed on a different hardware platform than the current PC might not run under Windows NTSome OS/2 applications are not compatible with Windows NT

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The Windows NT Registry

Hierarchical database containing all the hardware, software, device drivers, network protocols, and user configuration information needed by the OS and applicationsWays to look at Registry organization • Physical organization• Logical organization

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How the Registry Is Organized

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How the Registry Is Organized13

Logical Organization of the Registry

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The Windows NT Registry Editor

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Physical Organization of the Registry

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Subtrees on the Windows NT Registry

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Two Registry Editors

Regedt32.exeRegedit.exe

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Registry Editor13

Backing Up the Registry

Use Rdisk.exe to create an ERDMake a new ERD so that the Registry backup is up to date

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Installing Software and Hardware

Use the Windows NT Control PanelChanges are made to the Registry

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Installing Hardware

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Installing Hardware13

Windows NT Diagnostic Tools

Task ManagerEvent ViewerWindows NT Diagnostics

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The Task Manager

First introduced with Windows NT 4.0Allows you to monitor processes and applications running on the PC, and to start and stop themDisplays performance measurements (processor time, main memory and virtual memory size, number of threads) to help in diagnosing problems with poor performance

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The Task Manager

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The Task Manager13

The Task Manager

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The Event Viewer

Used to view a log that Windows NT created because of a failed eventTracks events as they are performed by the applications, the OS, services, or processes, and by user actions

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The Event Viewer

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The Event Viewer13

Windows NT Diagnostics

A graphical view of the Windows NT Registry showing hardware and OS data, which can be used to: • Resolve conflicts• Diagnose failed hardware• View information about drivers and

services that are loaded

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Windows NT Diagnostics13

Chapter Summary

Introduction to Windows NT (new technology)• Basic architecture• Installation• Maintenance• Troubleshooting

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Chapter Summary

Two versions of Windows NT• Windows NT Workstation

Can be used on a standalone PC or can be used as the operating system on a workstation connected to a network

• Windows NT ServerCan do the same, as well as provide a domain environment on the network

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Chapter Summary

Windows NT is architecturally more like UNIX OS than other Windows operating systemsWindows NT design• Emphasis on room for expandability (modular

approach)• Intended to port to several non-Intel-based

platforms• Provision of high level of security, performance,

and reliability• Offers strong networking features