PC Maintenance: Preparing for A+ Certification Chapter 27: The Boot Process

PC Maintenance: PC Maintenance: Preparing for A+ Preparing for A+

CertificationCertificationChapter 27: The Boot ProcessChapter 27: The Boot Process

Chapter 27 ObjectivesChapter 27 Objectives

Understand bootable disksUnderstand bootable disks Identify key boot files in each OS versionIdentify key boot files in each OS version List the boot sequence for each OSList the boot sequence for each OS Use alternative boot modesUse alternative boot modes Create and use a boot floppyCreate and use a boot floppy Use the Recovery ConsoleUse the Recovery Console Create and use an ERDCreate and use an ERD Troubleshoot startup and shutdown problemsTroubleshoot startup and shutdown problems

What Constitutes a Bootable What Constitutes a Bootable Disk?Disk?

A disk that can bring the PC to a functional A disk that can bring the PC to a functional level, with the OS ready to accept user level, with the OS ready to accept user commandscommands

Startup Configuration Files for Startup Configuration Files for DOSDOS

CONFIG.SYSCONFIG.SYS Used primarily under MS-DOSUsed primarily under MS-DOS Plain text filePlain text file Lists environment variables and device driversLists environment variables and device drivers Runs only at startupRuns only at startup

AUTOEXEC.BATAUTOEXEC.BAT Used primarily under MS-DOSUsed primarily under MS-DOS Plain text filePlain text file Lists applications to run at startupLists applications to run at startup Simple batch file, can be rerun at any timeSimple batch file, can be rerun at any time

Sample CONFIG.SYSSample CONFIG.SYS

Sample AUTOEXEC.BATSample AUTOEXEC.BAT

Startup Configuration Files for Startup Configuration Files for Windows 3.xWindows 3.x

SYSTEM.INISYSTEM.INI Loads device driversLoads device drivers Defines environment variablesDefines environment variables

WIN.INIWIN.INI Loads applicationsLoads applications Sets display settings and I/O device settingsSets display settings and I/O device settings Defines application settingsDefines application settings

Sample SYSTEM.INISample SYSTEM.INI

Sample WIN.INISample WIN.INI

The RegistryThe Registry

32-bit versions of Windows system 32-bit versions of Windows system settings filessettings files

In Windows 9x:In Windows 9x: SYSTEM.DAT and SYSTEM.DAT and USER.DATUSER.DAT

In Windows NT/2000/XP:In Windows NT/2000/XP: SAM, SAM, SECURITY, SYSTEM, SOFTWARE, SECURITY, SYSTEM, SOFTWARE, DEFAULTDEFAULT

Accessed through the Registry Editor as a Accessed through the Registry Editor as a single databasesingle database

MS-DOS Boot SequenceMS-DOS Boot Sequence

1.1. BIOS performs POSTBIOS performs POST2.2. BIOS searches for master boot record (MBR), BIOS searches for master boot record (MBR),

which defines the active partitionwhich defines the active partition3.3. MBR takes control and locates IO.SYSMBR takes control and locates IO.SYS4.4. IO.SYS takes control, identifies hardwareIO.SYS takes control, identifies hardware5.5. IO.SYS runs CONFIG.SYSIO.SYS runs CONFIG.SYS6.6. MSDOS.SYS takes control, loads OS kernel MSDOS.SYS takes control, loads OS kernel

into RAMinto RAM7.7. MSDOS.SYS runs AUTOEXEC.BATMSDOS.SYS runs AUTOEXEC.BAT8.8. Command.com displays a command promptCommand.com displays a command prompt

Windows 9x Boot SequenceWindows 9x Boot Sequence

1.1. BIOS performs POSTBIOS performs POST

2.2. BIOS searches for MBRBIOS searches for MBR

3.3. MBR takes control and locates IO.SYSMBR takes control and locates IO.SYS

4.4. IO.SYS takes control, runs MSDOS.SYS IO.SYS takes control, runs MSDOS.SYS instructionsinstructions

5.5. IO.SYS loads LOGO.SYS (graphic file) and IO.SYS loads LOGO.SYS (graphic file) and displays it as Windows “splash screen”displays it as Windows “splash screen”

6.6. IO.SYS looks for SYSTEM.DAT and USER.DAT IO.SYS looks for SYSTEM.DAT and USER.DAT and checks themand checks them


7.7. IO.SYS loads SYSTEM.DATIO.SYS loads SYSTEM.DAT

8.8. IO.SYS executes CONFIG.SYS and IO.SYS executes CONFIG.SYS and AUTOEXECB.BAT if presentAUTOEXECB.BAT if present

9.9. IO.SYS loads HIMEM.SYSIO.SYS loads HIMEM.SYS

10.10. IO.SYS loads WIN.COMIO.SYS loads WIN.COM

11.11. Win.COM loads 386.VXD (virtual Win.COM loads 386.VXD (virtual memory manager)memory manager)

12.12. VMM386.VXD loads 32-bit device driversVMM386.VXD loads 32-bit device drivers


13.13. WIN.COM processes SYSTEM.INI if WIN.COM processes SYSTEM.INI if presentpresent

14.14. WIN.COM loads KRNL32.DLL, GDI.EXE, WIN.COM loads KRNL32.DLL, GDI.EXE, and USER.EXEand USER.EXE

15.15. WIN.COM executes WIN.INI if presentWIN.COM executes WIN.INI if present

16.16. WIN.COM runs any programs from WIN.COM runs any programs from Startup folder on Start menuStartup folder on Start menu

Alternative Boot Modes for Alternative Boot Modes for Windows 9xWindows 9x

Press F8 as PC is starting up to see Press F8 as PC is starting up to see Startup MenuStartup Menu

Alternative Boot Modes for Alternative Boot Modes for Windows 9xWindows 9x

Safe ModeSafe Mode

Minimal Minimal set of set of driversdrivers

Standard Standard VGA VGA driverdriver

No No support support for CD, for CD, sound, sound, modemsmodems

Step by Step ConfirmationStep by Step Confirmation

Accept or reject each line of the startupAccept or reject each line of the startup

Windows NT, 2000, and XP Boot Windows NT, 2000, and XP Boot SequenceSequence

1.1. BIOS performs POSTBIOS performs POST2.2. BIOS searches for MBRBIOS searches for MBR3.3. MBR takes control and locates NTLDRMBR takes control and locates NTLDR4.4. NTLDR switches CPU into 32-bit protected NTLDR switches CPU into 32-bit protected

modemode5.5. NTLDR reads BOOT.INI. If multiple OSes, it NTLDR reads BOOT.INI. If multiple OSes, it

displays a menu for user choice, and passes displays a menu for user choice, and passes control to the chosen OScontrol to the chosen OS

6.6. NTLDR runs NTDETECT.COM, which detects NTLDR runs NTDETECT.COM, which detects the hardware for Registrythe hardware for Registry

Windows NT, 2000, and XP Boot Windows NT, 2000, and XP Boot SequenceSequence

7.7. NTLDR reads NTOSKRNL (OS kernel) NTLDR reads NTOSKRNL (OS kernel) into memory into memory

8.8. NTLDR locates drivers for Registry-NTLDR locates drivers for Registry-reported hardwarereported hardware

9.9. NTLDR hands over control to NTLDR hands over control to NTOSKRNL.EXENTOSKRNL.EXE

10.10. NTOSKRNL.EXE loads the device NTOSKRNL.EXE loads the device drivers and the GUIdrivers and the GUI

Alternative Boot Modes for NT 4Alternative Boot Modes for NT 4

VGA mode VGA mode

Alternative Boot Modes for Windows Alternative Boot Modes for Windows 2000 and XP2000 and XP

Troubleshooting 9x StartupTroubleshooting 9x Startup

No operating system foundNo operating system found No bootable disk is availableNo bootable disk is available PC does not see hard drivePC does not see hard drive Hard drive not formattingHard drive not formatting No OS installedNo OS installed Loose connection to hard diskLoose connection to hard disk Physical malfunctionPhysical malfunction Virus infectionVirus infection IO.SYS or MSDOS.SYS missing or corruptedIO.SYS or MSDOS.SYS missing or corrupted


Error in CONFIG.SYS Line xxError in CONFIG.SYS Line xx Driver called for in CONFIG.SYS missing or Driver called for in CONFIG.SYS missing or

corruptedcorrupted Bad or Missing COMMAND.COMBad or Missing COMMAND.COM Stuck at Windows splash screenStuck at Windows splash screen

Press Esc to see what is going on behind itPress Esc to see what is going on behind it Disable virtual memoryDisable virtual memory Rebuild paging fileRebuild paging file


Missing, Corrupt, or Unloaded Missing, Corrupt, or Unloaded HIMEM.SYSHIMEM.SYS

Windows protection errorWindows protection error Virtual device driver problemVirtual device driver problem Start in Safe Mode and check for a real-mode Start in Safe Mode and check for a real-mode

driver on CONFIG.SYSdriver on CONFIG.SYS Remove and reinstall the deviceRemove and reinstall the device

Device referenced in SYSTEM.INI or Device referenced in SYSTEM.INI or WIN.INI not foundWIN.INI not found


General protection fault (GPF)General protection fault (GPF) Two programs try to use the same memory Two programs try to use the same memory

spacespace Make a note of the file causing the error, and Make a note of the file causing the error, and

restartrestart If repeats, try reinstalling the associated If repeats, try reinstalling the associated

program or using EXTRACT to re-copy file program or using EXTRACT to re-copy file from Windows discfrom Windows disc

Troubleshooting 2000/XP StartupTroubleshooting 2000/XP Startup

Try Safe ModeTry Safe Mode Try restoring last known good Try restoring last known good

configurationconfiguration If Windows XP, use System RestoreIf Windows XP, use System Restore Repair Windows installation by booting Repair Windows installation by booting

from Setup CD and choosing Repairfrom Setup CD and choosing Repair

Controlling What Loads at Controlling What Loads at StartupStartup

Disable items in Disable items in WIN.INI, WIN.INI, SYSTEM.INI, SYSTEM.INI, AUTOEXEC.BAT, AUTOEXEC.BAT, and CONFIG.SYS and CONFIG.SYS through the through the System System Configuration Configuration Editor (SYSEDIT)Editor (SYSEDIT)


Delete items from Startup folder on Start menuDelete items from Startup folder on Start menu


Use System Use System Configuration Utility Configuration Utility (MSCONFIG) to (MSCONFIG) to disable startup disable startup itemsitems

Creating a 9x Startup FloppyCreating a 9x Startup Floppy

1.1. Open Control PanelOpen Control Panel

2.2. Add/Remove Programs, Startup Disk tabAdd/Remove Programs, Startup Disk tab

3.3. Click Create Disk and follow the promptsClick Create Disk and follow the prompts

How a Boot Floppy WorksHow a Boot Floppy Works

1.1. Booting from floppy creates RAM diskBooting from floppy creates RAM disk

2.2. Compressed files are decompressed onto Compressed files are decompressed onto RAM diskRAM disk

Therefore… some utilities are directly on Therefore… some utilities are directly on the floppy, and others are on the RAM diskthe floppy, and others are on the RAM disk

Files on a Boot FloppyFiles on a Boot Floppy DRVSPACE.BIN:DRVSPACE.BIN: Support for hard disks compressed Support for hard disks compressed

with DriveSpacewith DriveSpace EBD.CAB:EBD.CAB: The compressed file containing extra utilities The compressed file containing extra utilities

to be placed on RAM diskto be placed on RAM disk AUTOEXEC.BATAUTOEXEC.BAT and and CONFIG.SYSCONFIG.SYS FINDRAMD.EXE:FINDRAMD.EXE: Locates the RAM disk Locates the RAM disk EXTRACT.EXE:EXTRACT.EXE: Extracts compressed files to RAM disk Extracts compressed files to RAM disk FDISK:FDISK: Partitions disks Partitions disks README.TXT:README.TXT: Information Information CD-ROM driversCD-ROM drivers

Files on the RAM DiskFiles on the RAM Disk

What is an ERD?What is an ERD?

Emergency Repair DiskEmergency Repair Disk

For Windows 2000/XP onlyFor Windows 2000/XP only

Not bootableNot bootable

Stores settings that can help repair Stores settings that can help repair Windows, along with Windows Setup’s Windows, along with Windows Setup’s Repair modeRepair mode

Specific to that PCSpecific to that PC

Creating an ERDCreating an ERD

1.1. Start the Start the Backup Backup applicationapplication

2.2. Click the Click the Emergency Emergency Repair Disk Repair Disk buttonbutton

3.3. Follow the Follow the promptsprompts

What Is the Recovery Console?What Is the Recovery Console?

Command-line interfaceCommand-line interface Limited set of commandsLimited set of commands Accessible even when Windows will not Accessible even when Windows will not

start normallystart normally Can repair the MBR, disable services, etc.Can repair the MBR, disable services, etc.

Booting to the Recovery ConsoleBooting to the Recovery Console

1.1. Boot from the Windows CDBoot from the Windows CD

2.2. Choose R for RepairChoose R for Repair

3.3. Choose C for Recovery ConsoleChoose C for Recovery Console

4.4. Type 1 to choose the Windows installationType 1 to choose the Windows installation

5.5. Enter administrator password when Enter administrator password when promptedprompted

Recovery Console CommandsRecovery Console Commands

ATTRIBATTRIB CDCD MDMD COPYCOPY DELDEL CHKDSKCHKDSK

DIRDIR EXITEXIT EXPANDEXPAND FORMATFORMAT MDMD RDRD RENREN

Some are same as with Win9x startup disk:Some are same as with Win9x startup disk:

Recovery Console CommandsRecovery Console Commands

Some are different from normal command Some are different from normal command prompt commands:prompt commands: BATCHBATCH DISABLEDISABLE DISKPARTDISKPART ENABLEENABLE FIXBOOTFIXBOOT FIXMBRFIXMBR LISTSYSLISTSYS

Troubleshooting Shutdown Troubleshooting Shutdown ProblemsProblems

Does not shut off with Shut Down Does not shut off with Shut Down commandcommand Is ACPI enabled in BIOS Setup?Is ACPI enabled in BIOS Setup? Is it an ATX motherboard?Is it an ATX motherboard? Is ACPI enabled in Windows?Is ACPI enabled in Windows? Are case wires connected to motherboard?Are case wires connected to motherboard? Is a BIOS update available for motherboard?Is a BIOS update available for motherboard?


Application Not RespondingApplication Not Responding Click End Task if dialog box appearsClick End Task if dialog box appears Press Ctrl+Alt+Delete and shut down Press Ctrl+Alt+Delete and shut down

applicationapplication No Shutdown with Power ButtonNo Shutdown with Power Button

Hold power button down for 5 secondsHold power button down for 5 seconds


Windows 98 locks up when shutting downWindows 98 locks up when shutting down Download patch for Windows 98Download patch for Windows 98 Disable Fast Shutdown (in MSCONFIG)Disable Fast Shutdown (in MSCONFIG)

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PC Maintenance: Preparing for A+ Certification Chapter 27: The Boot Process