Chapter 12 Supporting Windows 9x
Jan 01, 2016
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
continued…
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
continued…
Tools Used to Monitor, Control, and Troubleshoot Windows 9x
continued…
Tools Used to Monitor, Control, and Troubleshoot Windows 9x
Keystroke Shortcuts in Windows
continued…
continued…
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
continued…
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
continued…
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
continued…
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