1. Understanding the Boot Process and Command Line
Chapter 3
Understanding the Boot Process and Command Line

2. You Will Learn…
To understand the process of booting to a command prompt
To create and use Windows 9x rescue disks to troubleshoot and solve problems when booting Windows
To use many commands at the command prompt

3. Understanding the Boot Process
When OS is functioning:
Interface: command driven, menu driven or icon driven
GUI (graphical user interface)
Desktop: menu & icon driven
Launch application using Windows Explorer to copy files or create folders & troubleshoot

4. Understanding the Boot Process
When OS is NOT functioning:
No desktop
Must use command driven interface
MS-DOS: real mode to boot computer
Command line: tried & true tool for worst OS problems
Essential to PC trouble shooting

5. Booting Up Your Computer
Refers to the computer bringing itself up to an operable state without user intervention
Soft (warm) boot : CTRL + ALT + DEL
Faster or Restart
Uses OS to reboot
Hard (cold) boot
Uses on/off switch
More stressful on the machine because of power surge

6. Booting Up Your Computer
Plug and Play (PnP) standard
File system
What happens when PC is first turned on and startup BIOS takes control and then loads OS
What happens when essential components of OS are loaded from hard drive or floppy disk

7. Plug and Play
Standard designed to make installation of hardware devices easier
Applies to OS, system BIOS, and hardware devices
Supported by Windows 9x and Windows 2000/XP but not by Windows NT
ESCD (extended system configuration data) Plug and Play BIOS: creates a list of all things you have done manually to the configuration the PnP doesn’t do
Last paragraph on page 78 and 1st paragraph on 79

8. What Is a File System?
Organizational method used by an OS to store files and folders on a secondary storage device
FAT (file allocation table) file system
Files and directories
File naming conventions
File organization
Partitions and logical drives on a hard drive

9. FAT File System
Most common file system for floppy disks and hard drives
Contains list of clusters and which clusters are used for each file stored on the disk
Tracks: concentric circles on the disk surface
Sector: each track is divided into these segments
Cluster: smallest unit of space on a disk for storing data

10. Tracks and Sectors

11. Files and Directories
Directory table:
Root Directory:

12. File Naming Conventions
Under DOS
Can contain up to eight characters, a separating period, and a file extension of up to three characters
a through z, 0 through 9, _ , ^, $, ~, !, #, %, &, -, {, }, --- do NOT use space, period, *, ? or \
Acceptable file extensions: .com, .sys, .bat., and .exe
Example: filename.ext
Under Windows 95 and later Windows OSs
Can be as long as 255 characters and can contain spaces

13. File Organization
Create different directories on a hard drive or other secondary storage media

14. Partitions and Logical Drives on a Hard Drive

15. Startup BIOS Controls the Beginning of the Boot
Boot steps
BIOS checking hardware
Loading the OS
OS initializing itself
Loading and executing an application
Startup BIOS is in control for first step of the boot, then it turns over control to the OS
Boot errors: communicated as beeps or messages (Appendix A)

16. Overview of Boot Steps Step 1: POST (Power-on self test)
Step 2: ROM BIOS startup program searches for and loads an OS
Step 3: OS configures the system and completes its own loading
Step 4: User executes application software

17. Boot Step 1: POST
Page 84

18. How the BIOS Finds and Loads the OS
Partition table:
Active partition:

19. Boot Step 2: Loading the OS

20. Loading the MS-DOS Core of Windows 9x
When only MS-DOS core of Windows 9x is loaded during booting
Brings OS to real-mode command prompt similar to DOS command prompt
Real-mode DOS core is often used as a troubleshooting tool when hard drive fails
Buffer:
Batch file:

21. Boot Step 3: OS Initializes Itself

22. Loading the MS-DOS Core of Windows 9x
When OS loads from hard drive, BIOS first executes the MBR, which executes OS boot record, which, for Windows 9x, attempts to find Io.sys on hard drive
Io.sys, which uses Msdos.sys, and Command.com, form the core of real-mode Windows 9x
All three are necessary to boot to a command prompt
Autoexec.bat and Config.sys contain commands used to customize 16-bit portion of Windows 9x load process
RAM drive

23. Emergency Startup Disks (ESDs)
Bootable Disk: floppy with enough software to load OS
Bootable disks with some utility programs to troubleshoot a failed hard drive
Also called rescue disk or startup disk
Created automatically by the OS beginning with Windows 95

24. Windows 9x Startup Disks

26. Files Contained in the Cabinet File, Ebd.cab

27. Windows 9x Startup Disks
Creating your own bootable rescue disk for Windows 9x
Using a Windows startup disk with another OS

28. Creating Your Own Bootable Rescue Disk for Windows 9x

29. Creating Your Own Bootable Rescue Disk for Windows 9x

30. Using the Command Prompt
Accessing a command prompt
Launching programs from the command prompt
Using commands to manage files and folders
Using utility tasks to troubleshoot a failed system

31. Ways to Access a Command Prompt
Click Start, Programs, MS-DOS Prompt
Click Start, Run, enter Command.com in the Run dialog box
When booting from a bootable disk or rescue disk, you get a command prompt instead of Windows desktop

32. Command Prompt Window

33. To Get a True Real-Mode Environment in Windows 9x
Click Start, click Shutdown, and select Restart in MS-DOS mode from Shutdown dialog box
Boot to a command prompt by holding down Ctrl or F8 while booting; select “Command prompt only” from the menu
Read paragraph on page 97

34. Launching a Program Using the Command Prompt
OS receives command to execute the application
OS locates the program file for the application
OS loads the program file into memory
OS gives control to the program
Program requests memory addresses from OS for its data
Program initializes itself; possibly requests that data from secondary storage be loaded into memory
Program turns to user for first instruction

35. Finding a Program File

36. Using the Path Command

37. Using Commands to Manage a Floppy Disk or Hard Drive
Dir
Type
Del or Erase
Undelete
Recover
Diskcopy
continued…
Wildcards:

38. Using Commands to Manage a Floppy Disk or Hard Drive
Copy
Xcopy /C /S /Y /D:
Deltree
Mkdir [drive:]path or MD [drive:]path
Chdir [drive:]path or CD [drive:]path or CD..
Rmdir [drive:]path or RD [drive:]path
continued…
Page 104 Tip

39. Mkdir Command
continued…

40. Using Commands to Manage a Floppy Disk or Hard Drive
Attrib
Unformat
Path
Sys Drive:
Chkdsk [drive:] /F /V
Scandisk Drive: /A /N /P
continued…

41. Using Commands to Manage a Floppy Disk or Hard Drive
Scanreg /Restore /Fix /Backup
Defrag Drive: /S
Ver
Extract filename.cab file1.ext /D
Debug
Edit [path][filename]
continued…

42. Using Commands to Manage a Floppy Disk or Hard Drive
Editing Autoexec.bat and Config.sys:
always make a rescue disk before editing
Don’t use a word processor to edit unless saved ad .txt file
Fdisk /Status /MBR
Fdisk: prepares HD for 1st use
Format Drive: /S /V:Volumename /Q /U /Autotest
continued…
Page 110 Tip

43. Edit Autoexec.bat
continued…

44. Options for the Fdisk Command
continued…

45. Options for the Format Command
continued…

46. Options for the Format Command

47. Using Batch Files
To execute a group of commands using only a single command to execute the batch file

48. Chapter Summary How a PC first boots up and loads the operating system
How to create floppy disks that can be used to boot to a command prompt
Essential commands for troubleshooting a failing system