Chapter 12

Supporting Windows 9x

You Will Learn…

About the Windows 9x architecture How to install Windows 9x and how to install

hardware and applications using Windows 9x About tools for using and managing

Windows 9x About the Windows 9x boot process How to troubleshoot Windows 9x

Windows 9x Architecture

Shell• Portion of the OS that relates to the user and to applications

• Provides a command, menu, or icon interface to the user

Kernel (core)• Interacts with the hardware

• Applications cannot get to hardware devices without the shell passing those requests to the kernel

Important Parts of the Shell

User component manages:• Input from the keyboard and other user devices

• Output from the user interface

• The GDI

GDI (Graphics Device Interface)• Presents graphical interface to the user and

provides graphics support to output devices

Core Components of Windows 9x

Windows 9x Architecture

Configuration data primarily stored in the registry, a database that contains:• Initialization information for applications• Database of hardware and software settings• Windows configuration settings• User parameters• Application settings

Some data is kept in text files called initialization files (.ini or .inf extension)

Windows 9x Architecture

Virtual Machines

Set of resources made available to an application through predefined application programming interface (API) calls

Multiple logical machines within one physical machine

Windows 9x Architecture

Modular approach• Divides functions into separate program groups

• Makes each component easier to update and implement

Components of Windows 9x

VMM (Virtual Machine Manager) IFS (Installable File System) manager Configuration Manager WDM (Win32 Driver Model) driver manager

Installing Windows 9x

Contents of installation CD Preparing the hard drive for installation

Contents of Windows 9x CD

Files for:• Installing the OS

• Customizing configuration of OS

• Configuring and optimizing the desktop

• Network administration

• Diagnosing and troubleshooting system errors

• File management

Windows 98 CD

Important Folders on the Windows 9x CD

CD sample Drivers Oldmsdos Sysrec

Important Files on theWindows 9x CD

Preparing for Installation: Hardware Requirements

Types of Installations

Clean install Upgrade install

Installing Windows 9x as aClean Installation

Ignores settings in currently installed OS; all hardware and applications must be reinstalled

Verify you have all application software installation CDs or floppy disks

Back up all data on drive May need to change boot order in CMOS

Installing 9x as an Upgrade

Verify hard drive space Run ScanDisk and antivirus software Check Config.sys and Autoexec.bat for potential problems Disable TSRs that might cause problems Verify that network connection is working Create rescue disk (from Windows 95 to 98) Decide whether to use FAT16 or FAT32 Put swap file on drive compressed with protected-mode

software

Installation Process from Setup Screen

Setup options• Typical• Portable• Compact• Custom

Records information in log files• Setuplog.txt• Detlog.txt• Detcrash.log

Setuplog.txt Log File

Detlog.txt Log File

Configuring Windows 9x Startup with Msdos.sys

Msdos.sys contains several parameters that affect how OS boots

To edit Msdos.sys, first change file attributes

Msdos.sys File Options Contents

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Sample Msdos.sys File

Upgrading from Windows 95 to Windows 98

Guidelines• Check hardware and software for compatibility• Run antivirus software; back up system

Perform the upgrade• Disable system BIOS program that protects boot sector (if

applicable)• Start Windows 95 and close applications• Insert upgrade CD and run C:\Setup; follow prompts• Test applications; back up again

Download/install updates from Microsoft Web site

Installing Hardware with Windows 9x

Found New Hardware Wizard launches automatically when a new device is installed and you power up

Installing Hardware with Windows 9x

Viewing and Changing Current Device Drivers

Viewing and Changing Current Device Drivers

Viewing and Changing Current Device Drivers

Plug and Play (PnP)

Set of design specifications for hardware and software that works to make hardware installations effortless

Criteria• System BIOS must be PnP

• All hardware devices and expansion cards must be PnP-compliant

• OS must be Windows 9x or another OS that supports PnP

• 32-bit device driver must be available

Why 9x Works Better Using32-bit Drivers and Applications

Generally faster than 16-bit software Can be stored in extended memory, releasing

more of the first megabyte of memory 32-bit drivers can be loaded automatically;

conserves memory 32-bit applications can share data with other

32-bit applications; better use of resources

Installing Applications in Windows 9x

Preparing for software installation Performing software installations Troubleshooting software installations Supporting DOS applications under

Windows 9x

Preparing for Software Installation

Check available resources Protect original software Back up registry and system configuration files

Performing Software Installations

Use Add/Remove Programs icon from Control Panel After installation is complete and software is working,

update backup copies of:• Autoexec.bat

• Config.sys

• System.ini

• Win.ini

• Registry

Troubleshooting Software Installations

If application locks up when first opened, delete all files and folders under \Windows\Temp

Look at Readme.htm hypertext file in \Windows directory

Supporting DOS Applications Under Windows 9x

Use Properties feature of DOS program file, which will:• Create an individual PIF file for the program file

• Serve as the PIF editor

Supporting DOS Applications Under Windows 9x

Real Mode vs. Virtual Real Mode

An OS that supports protected mode can allow a 16-bit program that is written to work in real mode to run in virtual real mode

In virtual real mode, the program “thinks” that:• It is the only program running

• It has all memory available to it

• It accesses data using a 16-bit data path

Virtual Real Mode

Tools Used to Monitor, Control, and Troubleshoot Windows 9x

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Tools Used to Monitor, Control, and Troubleshoot Windows 9x

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Tools Used to Monitor, Control, and Troubleshoot Windows 9x

Keystroke Shortcuts in Windows

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Keystroke Shortcuts in Windows

Keystroke Shortcuts in Windows

Managing theWindows 9x Desktop

Make applications automatically load at startup Create shortcuts to files and applications

• User clicks an icon to load software

Make environment more user-friendly

Display Properties Window

Taskbar Properties Window

Working with Shortcuts

Managing Icons

Managing Icons

Device Manager

Gives graphical view of hardware devices configured under Windows and the resources and drivers they use

Can be used to:• Make changes• Update drivers• Uninstall device drivers• Print a report of system configuration

Device Manager

Dr. Watson

Records detailed information in a log file about:• The system

• Errors that occur

• Programs that caused the errors

The Windows 9x Registry

Organizes information in a hierarchical database of configuration information and settings for users, hardware, applications, and the OS

Takes over essential functions of .ini files• Still supports System.ini and Win.ini for backward

compatibility

Windows 9x System.ini File

How the Registry Is Organized

How the Registry Is Organized

Recovering froma Corrupted Registry

Windows 95 backup of the registry• Maintains a backup copy of the two registry files and

names them System.da0 and User.da0

• If Windows 95 has trouble loading and starts in safe mode, it does not back up the registry

Windows 98/Me Registry Checker• Utility that automatically backs up the registry every day

• Keeps the last five days of backups

The Registry Checker

Repairing or Recovering the Registry

Modifying the Registry

Automatic when a change is made in Control Panel or Device Manager or when software is installed

Use Regedit utility to edit the register manually

Managing Memory with Windows 9x

Organized as conventional, upper, and extended as it is in DOS

Windows 9x—mostly a 32-bit OS—“lives” in extended memory together with its device drivers and applications and only uses base and upper memory for 16-bit components

Windows 9x Swap File

Virtual Machine Manager (VMM) Manages memory paging, which involves swapping

blocks of memory stored in RAM to the hard drive Terminology

• Page fault• Page-in• Page-out

Symptoms of disk thrashing• Very high CPU use• Very slow system response• Constant hard drive use

How Windows Manages Memory

Booting Windows 9x

Files Used to Customize the Startup Process• For backward compatibility with DOS

• Autoexec.bat• Config.sys

• Initialization files

Editing Windows System Files

The Windows 9x Startup Process

First loads in real mode; switches to protected mode• Io.sys is responsible for initial startup (real mode)• Control is turned over to Vmm32.vxd (protected mode) and

Io.sys is terminated

Five-phase process• Phase 1: BIOS POST and Boostrap• Phase 2: The OS is Loaded• Phase 3: Static VxDs• Phase 4: Protected-mode switchover and PnP configuration• Phase 5: Loading the remaining components

Default Io.sys Entries

Loading an Applicationat Startup

Place shortcut in Startup folder Put name of program in Load= or Run= line in

Win.ini Manually edit registry key

HKEY_LOCAL_MACHINE\SOFTWARE\ Microsoft\Windows\CurrentVersion\Run

Troubleshooting Installations

Basic Steps for Troubleshooting the Windows 9x Boot Process

Check and address error messages Boot in safe mode Boot to command prompt using startup menu Try booting from emergency startup disk

Error Messages Received While Loading Windows 9x

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Error Messages Received While Loading Windows 9x

Tools for Troubleshooting Problems with Booting

System Configuration Utility (Msconfig)• Reduces startup process to its essentials to attain cleanest

possible boot

Device Manager• Disables a device

Automatic Skip Driver Agent (ASDA)• Keeps Windows from installing a driver that might be corrupted

Windows 9x startup menu• Includes safe mode, the command prompt, and other

troubleshooting options

Windows 9x Startup Menu Options

1. Normal2. Logged (\BOOTLOG.TXT)3. Safe Mode4. Safe Mode with network support5. Step-by-step confirmation6. Command prompt only7. Safe Mode command prompt only8. Previous version of MS-DOS

Bootlog.txt File

Safe Mode

Using Scan Disk in Safe Mode

Using Command Prompt Only

Troubleshooting withthe Startup Menu

Troubleshooting Windows 9x Hardware and Software

Ask the user questions Reboot Check for intermittent memory errors using memory

testing software Turn on devices before turning on the computer Try the device with another application Use Check Device Manager to check for errors or to

uninstall and reinstall the device

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Troubleshooting Windows 9x Hardware and Software

Check the Web for updated device drivers Consider lack of resources Check the registry key

HKEY_LOCAL_MACHINE\SOFTWARE\ Microsoft\Windows\CurrentVersion\Run

Check hard drive Suspect a virus

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Troubleshooting Windows 9x Hardware and Software

Close applications not currently in use Keep System Tray icons to a minimum Clean up registry with Scanreg /opt command Remove extraneous software Uninstall and reinstall problem software

applications; search Web site of manufacturer for fixes and upgrades

Windows Help andthe Microsoft Web Site

Windows Help• Access Troubleshooting tool via Start – Help –

Troubleshooting

Microsoft Web Site• support.microsoft.com

Windows Help

Microsoft Web Site

Chapter Summary

How Windows 9x is structured How it is used How it works with various software programs

and hardware devices How to troubleshoot