WINDOWS 1002000 PROFESSIONAL RESOURCE KIT [Electronic resources] نسخه متنی

Windows 2000 Professional Startup Process

The Windows 2000 startup process is similar to the startup process for Windows NT 4.0 but is significantly different from other operating systems. In MS-DOS, Windows 95, and Windows 98, the computer loads the IO.sys file followed by Msdos.sys and Command.com. However, in Windows 2000, these files only exist on computers that have multiple-boot configurations with Windows 95, Windows 98, or MS-DOS.

The following list describes the startup sequence on a computer running Windows 2000 Professional:

Power-on self test (POST)

Initial startup process

Bootstrap loader process

Operating system selection (if the computer has a multiple-boot configuration)

Hardware detection

Hardware configuration selection (if you are using more than one hardware profile)

Kernel loading

Operating system logon process

NOTE

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The system startup sequence only applies to a system that is started from a reboot or a power off state. This sequence does not apply to a system that is turned on from a hibernated state.

This startup sequence applies to all versions of Windows 2000.

Power-on Self Test

When a computer is started or reset, it runs the power-on self test (POST), which determines the amount of memory in the computer and checks that required hardware devices, such as the keyboard, are present and functioning. After the POST sequence, adapters that have their own basic input/output system (BIOS) run individual POST routines.

NOTE

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Some adapters (for example, some video adapters) run their POST sequence before the memory and device check, which runs during the initial POST.

Starting the Computer

After the computer finishes the POST, the system BIOS attempts to start an operating system. The sequence that the BIOS follows depends on the BIOS configuration. For example, if the BIOS search order is set to A and then C (A, C), the BIOS searches the floppy disk drive for a bootable disk. If drive A contains a bootable floppy disk, the BIOS loads its first sector (the partition boot sector) into memory. If the floppy disk is not bootable, the following error message appears.

Non-system disk or disk error
Replace and press any key when ready

If the BIOS does not find a floppy disk in the drive, it then searches for the active partition on the hard disk drive. If there is no system partition on the first hard disk, the master boot record (MBR) displays one of the following errors:

Invalid partition table

Error loading operating system

Missing operating system

When the active partition of the hard drive is found, the system BIOS reads the MBR and loads it into memory. The MBR then scans the partition table for the system partition information. When the system partition information has been read, it loads sector 0 of the system partition into memory and starts it.

NOTE

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Sector 0 of the system partition can be a utility, a diagnostic program, or a partition boot sector that contains the startup code for the operating system.

The system partition must be on the first physical disk and contain the system startup files listed in Table 6.1.

Table 6.1 Windows 2000 Startup Files

NOTE

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If the name of the path in Boot.ini uses small computer system interface (SCSI) syntax, the Ntbootdd.sys must be in the root folder of the system partition.

The boot partition can be on the same partition as the system partition, on a different partition, or on a different hard disk.

For the most part, the MBR is independent of the operating system. For example, the MBR can start Windows NT, Windows 95, Windows 98, MS-DOS, Microsoft® Windows® 3.x, and Windows 2000 Professional. However, after boot sector 0 has been loaded into memory, the partition boot sector is dependent on both the operating system and the file system. The Windows 2000 partition boot sector performs the following functions:

Reads the file system to find the bootstrap loader.

Loads the bootstrap loader into memory.

Starts the bootstrap loader.

Ntldr loads the operating system files from the boot partition. If you have a multiple-boot configuration, you are prompted to choose an operating system.

Ntldr controls the operating system selection and the hardware detection process before passing control to the Windows 2000 kernel. Ntldr must be in the root folder of the startup disk.

Ntldr performs the following steps:

Sets the processor to run in 32-bit flat memory mode. When you first start a computer, it runs in real mode, which is similar to an 8088 or 8086 CPU. Because Ntldr is a 32-bit program, it must switch the processor to 32-bit mode so that it can continue to load the operating system.

Starts the NTFS file system or the file allocation table (FAT) 16 or 32 file system. The code to access the appropriate file system is built into Ntldr.

Reads Boot.ini, which displays the operating selections on the boot loader screen. If you select an operating system other than Windows 2000 Professional, Ntldr loads and passes control to the Bootsect.dos file, and the selected operating system starts. if you select Windows 2000 Professional, Ntldr starts Ntdetect.com, which gathers information about the computer hardware.

Asks you to choose a hardware profile if you have one or more hardware profiles on your computer.

Loads and passes the information from Ntdetect.com to Ntoskrnl.exe, starting the startup screen.

Boot.ini contains the list of available operating systems. Each entry includes the path to the boot partition for the operating system, the string to display in the boot loader screen, and optional parameters. Boot.ini supports starting multiple versions of Windows 2000, as well as starting other operating systems, such as Windows 95, Windows 98, Windows NT 4.0, MS-DOS, and OS/2.

When you install Windows 2000, Setup places Boot.ini at the root of the system partition.

The following is a sample Boot.ini file:

[boot loader]
timeout=30
default=multi(0)disk(0)rdisk(0)partition(1)WINNT
[operating systems]
multi(0)disk(0)rdisk(0)partition(1)winnt= "Microsoft Windows 2000 Professional" /fastdetect
C:="Windows 98"

The information displayed on the boot loader screen is based on the contents of Boot.ini, such as in the following example:

Please select the operating system to start:
Microsoft Windows 2000 Professional
Microsoft Windows 98
Use ↑ and ↓ to move the highlight to your choice.
Please Enter to choose.
Seconds until highlighted choice will be started automatically: 29
For troubleshooting and advanced startup options for Windows 2000, press
F8.

The first operating system listed is the default. In this configuration, if you do not select an operating system before the timer reaches 0, Windows 2000 Professional is started.

Hardware Detection

After you select the operating system, Ntdetect.com detects the hardware, gathers a list of the currently installed hardware components, and passes the information to Ntldr.

Ntdetect.com detects the following components:

Computer Id

Bus/adapter type

Video adapter

Keyboard

Communications ports

Floppy disks

Mouse or other pointing devices

Parallel ports

During the Ntdetect phase, if you have multiple hardware configurations, the following information appears:

Hardware Profile/Configuration Recovery Menu
This menu allows you to select a hardware profile
to be used when Windows 2000 is started.

NOTE

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Profiles are only necessary under non–Plug and Play conditions. Plug and Play negates the need for profiles.

The bootstrap loader pauses for a few seconds or until you press Enter. If you have only one hardware profile, Windows 2000 Professional uses the default settings.

Windows 2000 Professional automatically uses the default settings if you do not select a hardware profile. When the default configuration is used, the bootstrap loader uses the registry information that Windows 2000 Professional saved at the completion of the last shutdown. After you select a hardware profile, Ntdetect.com passes control back to Ntldr.

Loading and Initializing the Kernel

During the next phase, Ntldr loads the kernel and the hardware abstraction layer (HAL) into memory. Next the bootstrap loader loads the registry key HKEY_LOCAL_MACHINESYSTEM from the folder %SystemRoot%system32ConfigSystem. Ntldr creates the control set that it uses to initialize the computer. The loader uses the control set identified by the default value unless you choose the Last Known Good Configuration from the Hardware Profiles screen.

The kernel initiates the Windows 2000 Professional screen, and the Starting Up progress bar is displayed. When the status bar completes, Ntoskrnl prepares the network information.

The kernel uses the information that was passed from the boot loader to create the HKEY_LOCAL_MACHINEHARDWARE key, which contains the hardware data that is collected at system startup. The data includes information about various hardware components on the motherboard and the system interrupts allocated by each device.

The kernel then creates the Clone control set, which is a copy that points to the Current control set. The Clone control set represents the state of the computer during configuration and is not changed or modified.

Logging On to the Operating System

The Windows subsystem automatically starts Winlogon.exe, which starts the Local Security Administration. The Begin Logon dialog box appears. Windows 2000 might still be initializing network device drivers, but you can log on.

The Service Controller searches the registry for services that are configured to load automatically. Autoload services have a Start value of 0x2 in the subkey HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesDriverName.The services that are loaded during this phase are loaded in parallel and so are loaded based on their dependencies. The dependencies are described in the DependOnGroup and DependOnService entries in the subkey HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesDriverName.

NOTE

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Windows 2000 startup is not considered complete until a user successfully logs on to the system. After a user logs on, the Clone control set is copied to the LastKnownGood control set.

Understanding the Boot.ini Naming Convention

Windows 2000 uses the Advanced Reduced Instruction Set Computing (RISC) naming convention to define the path to a Windows 2000 installation.

Using ARC Pathnames

The Advanced RISC Computing (ARC) pathnames in Boot.ini point to the location of the boot partition for all Windows 2000 installations. A single line in Boot.ini represents each installation. During the startup process, the boot loader screen prompts you to choose an installation.

The ARC names in the file Boot.ini are similar to the following:

Multi(W)disk(X)rdisk(Y)partition(Z)%systemroot%

Scsi(W)disk(X)rdisk(Y)partition(Z)%systemroot%

Signature(8b467c12)disk(1)rdisk(0)partition(2)%systemroot%="description"

Windows 2000 Professional can use any of these formats in Boot.ini to locate the SystemRoot directory.

Multi Syntax

This form of the ARC pathname is referred to as Multi. On Microsoft® Windows NT® version 3.1, Multi syntax was only valid for Integrated Device Electronics (IDE), Enhanced Integrated Drive Electronics (EIDE), and Enhanced Small Device Interface (ESDI) disks. In Microsoft® Windows NT® version 3.5 and later (including Windows 2000), it is also valid for small computer system interface (SCSI) disks. It is not used with Windows 95 or Windows 98.

The Multi syntax instructs Windows 2000 Professional to rely on the system BIOS to load system files. This means that Ntldr is using interrupt (INT) 13 BIOS calls to find and load Ntoskrnl.exe and any other files it needs to start the system.

The following is an example of the Multi syntax :

multi(W)disk(X)rdisk(Y)partiton(Z)

Table 6.2 describes the parameters used in the Multi syntax:

Table 6.2 Multi Syntax Parameter Variables

In theory, the Multi syntax can start Windows 2000 from any disk. However, this requires that all connected disks use the INT 13, and the system BIOS usually identifies only one disk adapter with INT13. For this reason, you can only use the Multi syntax to start Windows 2000 Professional from either of the two disks on the primary IDE or SCSI device or on the secondary IDE or SCSI device.

The use of the Multi syntax depends on the type of adapter that your computer uses. For example:

On IDE adapters, the Multi syntax works for up to four disks: two on primary and two on secondary IDE channels.

On SCSI adapters, the Multi syntax works for the first two disks on the first SCSI adapter (the adapter whose BIOS loads first).

With both SCSI and IDE adapters, the multi syntax works for only the IDE disks on the first adapter.

The SCSI syntax tells Windows 2000 Professional to load a SCSI device driver to access the boot partition.

The SCSI syntax is as follows:

scsi(W)disk(X)rdisk(Y)partition(Z)

Table 6.3 defines the parameters used in the SCSI syntax:

Table 6.3 SCSI Syntax Parameters

Signature Syntax

The Signature syntax is equivalent to the SCSI syntax but is used instead to support the Plug and Play architecture in Windows 2000. Because Windows 2000 is a Plug and Play operating system, the SCSI controller number instance might vary each time you start Windows 2000, especially if you add new SCSI controller hardware after Setup.

The Signature syntax instructs Ntldr to locate the drive with a disk signature that matches the value in the parentheses, regardless of which SCSI controller number that the drive is connected to.

The naming format in Boot.ini starts with Signature syntax. For example:

signature(8b467c12)disk(1)rdisk(0)partition(2)winnt="description" 

The Signature syntax is used only if one of the following conditions exists:

The partition on which you installed Windows 2000 is larger than 7.8 gigabytes (GB) in size, or the ending cylinder number is higher than 1024 for that partition, and the system BIOS or boot controller BIOS does not support extended INT13.

The drive on which you installed Windows 2000 is connected to a SCSI controller whose BIOS is disabled, so INT13 BIOS calls cannot be used during the startup process.

The Signature value is extracted from the MBR. This unique hexadecimal number is either written to the MBR during the text-mode portion of Setup or by a previous installation of Windows NT 4.0 or earlier.

Ntbootdd.sys

Ntbootdd.sys is a copy of the SCSI device driver and resides on the system partition. Ntbootdd.sys is used when using the SCSI or Signature syntax in the file Boot.ini.

Additionally, if you have multiple SCSI controllers that use different device drivers, include only the controllers that are controlled by Ntbootdd.sys when determining the value of the W parameter. For example, if you have an Adaptec 2940 controller (which uses Aic78xx.sys) and an Adaptec 1542 controller (which uses Aha154x.sys), the value of W is always 0. Ntbootdd.sys changes in the following situations:

If you load Windows 2000 professional from a disk on the Adaptec 2940 controller, Ntbootdd.sys is a copy of Aic78xx.sys.

If you load Windows 2000 professional from a disk on the Adaptec 1542 controller, Ntbootdd.sys is a copy of Aha154x.sys.

When you install Windows 2000 Professional, Boot.ini sets the system and hidden attributes for you. You can edit the time-out and default parameters in Boot.ini by using the System option in Control Panel.

IMPORTANT

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Back up the original Boot.ini file before making any changes.

To view Boot.ini, you must be able to view hidden files in My Computer.

To show hidden files in my computer

On the Tools menu, click Folder Options, and then click the View tab.

Clear Hide protected operating system files.

Click OK.

To edit the file Boot.ini, you can use Windows Explorer and double-click Boot.ini, or you can open any text editor to edit the file.

If you change the path to the Windows 2000 boot partition, edit the entries for both the default path and the operating system path. If you change only one, a new choice is added to the boot loader screen with the default designator next to it.

Driver Cabinet File

A cabinet (.cab) file is a compressed file that contains other distribution files, such as drivers and system files. Drivers are placed in a single .cab file on the Windows 2000 operating system CD. This driver .cab is used by both Setup and other system components that need to install drivers. The .cab file contains approximately 3000 files and is installed at:

%windir%Driver Cache<platform>driver.cab

The list of files is in Drvindex.inf. To view the .cab file, use Windows Explorer.

The benefits of using a .cab file include the following:

Does not require administrators to use a setup CD to install new devices on the computer.

Does not require you to log on with local admin rights to install new hardware as long as the device is present in the .cab file and digitally signed. You can override this by deleting the .cab file from the drive.

Reduces the amount of bandwidth and installation time that is required for network installations. (Winnt32.exe and Winnt.exe copy a single file instead of many smaller files.)

Provides a simple way to install printer drivers. Administrators do not need to have the Windows 2000 CD to install printer drivers because most printer manufactures use Microsoft core printer drivers. For mobile users, the printer drivers are always available for quick printing.

Enables remote install services clients to install drivers for new devices locally. It also allows the remote installation feature to support different hardware between the source computer used to create the image and the destination computer installing that image. For more information about Remote Installation Services, see "Customizing and Automating Installations" in this book.

When a driver file is needed, Setup checks the Drvindex.inf file to see if the file is listed. If the file is listed and the .cab file is on your computer, Setup tries to copy the file from the .cab file. If a signed driver file is found in the driver cache directory and has the same name as the needed file, Setup uses this file instead of the one contained in the .cab file. If the required file does not exist in the directory of the .cab, the installation path is searched. If that fails, Setup prompts you to supply the required file.