Boot Process of Windows 9x

Introduction to the boot process

• There are a number of steps involved in the boot process of windows 9x .These steps involve you selecting the loading option of choice including normal, safe, and ms-dos mode.

• The file MSDOS.SYS  can also be used to set your menu boot options in windows 95/98 if required.

Key Topics

Windows 9x boot process Windows 9x Startup options Startup Logged mode Startup safe mode Startup safe mode  with Networking

Startup Step by step confirmation Startup MSDOS mode MSDOS.SYS  file Purpose of MSDOS.SYS  file Changing MSDOS.SYS  file.

 

The installation  process is divided in to two major portions, The real DOS  mode and the protected GUI mode .

Windows 9x Boot Process  Real mode

• The system performs the Power  On Self Test (POST ) operations.

• The system load IO.SYS  

• IO.SYS  loads real mode  Operating System

• Sets environment variables

• Runs Config.sys  and Autoexec.bat

• Loads MSDOS.SYS  (load order)

• Loads system drivers

• HIMEM .SYS  (use extended memory - above 1MB)

• IFSHLP .SYS  (16 bit  programs  to access file system)

• SETVER.EXE (Allows older DOS  programs  to load)

• DRVSPACE.BIN  (Make Compressed drives transparent)

• Loads COMMAND.COM  (Internal Commands)

• Loads WIN.COM

 

Windows 9x Boot Process  loading Drivers

• Once the WIN.COM  program has been loaded, the system starts the protected GUI mode  and loads the following components

• Loads virtual memory  drivers  such as VMM32.VXD  and virtual device drivers (VXD) etc

• The IO.SYS  file is ended

• Loads other VXD  device drivers  that exist in different folders ,

• The system loads the registry , and INI  files

• Finally the system loads the configuration manager which loads the following components

Windows 9x Boot Process  Configuration Manager

• Loads configuration Manager

• Configures and loads legacy  and Plug and Play  VXD  drivers .

• Loads Core Windows files

• Kernel  (KERNEL32.DLL , KRNL386.EXE)

• GDI  (GDI.EXE, USER 32.DLL )

• Loads system fonts

• Load SYSTEM.INI  for upgraded systems

• Loads system shell, and then the desktop

• Loads logon  screen in a networked system.

Windows 98 startup  Options

• You can view the startup  options in Windows 95 by pressing F8, and in Windows 98 by pressing the CTRL in the boot process. The startup options include Normal , Logged mode , Safe mode, Safe mode with networking, Step by step confirmation, Command prompt, Safe mode command prompt , and previous version of DOS .

• Normal  

This mode load all installed components of windows without any errors .

• Startup Logged Mode

This mode loading process is traced and logged in the BOOTLOG.TXT  file for troubleshooting )

• Startup Safe Mode

This mode load the OS with minimal drivers  to view the GUI only for the purpose of reconfiguring the system to function normally.

 

• Startup Safe Mode with Networking

This mode is the same as safe mode  with added networking features which is only available on Windows 95.

• Startup Step by Step Confirmation

Within this mode you must confirm the loading of the components of windows as it loads IO.SYS , CONFIG.SYS, and AUTOEXEC.BAT .

• Startup Command Prompt

This mode load only real mode  components, CONFIG.SYS  and AUTOEXEC.BAT . This mode allows you to load all DOS  programs  both from the hard drive  and the CD -ROM  drive, and load any other device driver  added to the config.sys and autoexec.bat

• Startup Safe Mode Command Prompt

This mode load only real mode  components so that we obtain a command prompt , no extended memory  or CD -ROM  drive is available by default and is ideal for troubleshooting  real mode driver  problems.

• Startup Previous version of MS-DOS

This mode load previous version of DOS  that was installed before windows.

This result in windows not being loaded at all, this option is only available if Window was installed after DOS .

Boot process key options

• The table shows the different shortcut boot options.

 

 

 

 

 

 

 

 

 

 

 

 

MSDOS.SYS  in DOS

• MSDOS.SYS  inside DOS  is part of the system kernel and is a binary  file. MSDOS.SYS  inside DOS contains programs  interfacing with hardware, run applications , and manage files .

MSDOS.SYS  in Windows 9x

• Windows 95/98  IO.SYS  does all the required tasks of the kernel, therefore MSDOS.SYS  is no longer required in its initial role.

• MSDOS.SYS  is a hidden  read  only  text file performing two major tasks in windows 95/98:

• MSDOS.SYS  exists for backwards compatibility purposes

• It can be used to provide a menu at the start up of windows 95/98.

• The file MSDOS.SYS  has two main sections:

• The path  section (informs windows of where to find the different components)

• The options section (modifying the boot process).

    MSDOS.SYS  boot options

• Here are some MSDOS.SYS  menu options

   

Changing the options of MSDOS.SYS

• MSDOS.SYS  is a hidden  read  only  file. This means that the check for hidden and read only must be removed from the file.

• The files  can now be modified in notepad and then saved.

• The file must then be made hidden  and read  only  again before the system reboots.

Exercise (Changing the View options to view all files )

VIEWING HIDDEN FILES Exercise (Changing the View options to view all files )   Double click My Computer Double click on the C: Drive From the Menu options, select View and move your cursor to the folder options and click on it. From the folder options window, select the view tab from the top of the screen. From the Advanced settings section of the window under the subheading of hidden  files  and folders . Select Show All Files. Click on Apply, then OK. You should now be able to view all system files .

Exercise (Viewing file properties and changing file attributes)

Viewing File Properties Locate the MSDOS.SYS  file from the C: drive Right click on the file and choose the properties option from the drop down menu On the properties window of the MSDOS.SYS  file deselect the hidden  and read  only  attributes of the file by un-checking the check boxes.

 

Exercise (Changing the content of the MSDOS.SYS  file)

Double click on the MSDOS.SYS  file On the open with window choose the Notepad application. Once the file is open in Notepad, make the following changes to the file under the options heading. Add BootMenu =1 (To present a menu option on the screen) Add BootMenuDefault=1 (Select the first option in the menu list ) Add BootMenuDelay=15 (wait 15 seconds to make changes on the boot option)

Exercise (Add the hidden  attribute  of a file)

Locate the MSDOS.SYS  file from the C: drive Right click on the file and choose the properties option from the drop down menu On the properties window of the MSDOS.SYS  file select the hidden  and read  only  attributes of the file by checking the check boxes.

 

Questions

 

1. What key needs to be pressed for the boot menu

1. F8

2. F5

3. CTRL+F8

4. F4

5. F6

2. What key needs to be pressed for the safe mode

1. F8

2. F5

3. CTRL+F8

4. F4

5. F6

3. What key needs to be pressed for previous version of DOS

1. F8

2. F5

3. CTRL+F8

4. F4

5. F6

 

4. What key needs to be pressed for safe mode  with networking

1. F8

2. F5

3. CTRL+F5

4. F4

5. F6

5. What is the true about the MSDOS.SYS  file in Windows 95 ? (Choose all that apply)

1. It contains the options for the boot menu

2. It is a windows kernel file

3. It exist for backward compatibility

4. It’s a binary  file

5. It’s a text file

6. Why would you use the safe mode

1. Attempt to resolve problems which do not allow real mode  to load

2. Attempt to resolve problems which do not allow normal mode to load

3. To test unreliable programs

4. To test unreliable hardware

5. Down load important data from network

Answers

1.      A

2.      B

3.      D

4.      E

5.      A,E

6.      B