INSTALL WINDOWS XP PROFESSIONAL FROM A MASTER IMAGEIN THIS EXERCISE, Y...

4-15Lesson 2 Editing the Registry

Lesson 2: Editing the Registry

Windows XP Professional stores hardware and software settings centrally in a hierar-

chical database called the Registry, which replaces many of the .ini, .sys, and .com con-

figuration files used in earlier versions of Windows. The Registry controls the Windows

XP Professional operating system by providing the appropriate initialization informa-

tion to boot Windows XP Professional, to start applications, and to load components

such as device drivers and network protocols.

Most users of Windows XP Professional never need to access the Registry. However,

management of the Registry is an important part of the system administrator’s job, and

includes viewing, editing, backing up, and restoring the Registry. You use Registry Edi-

tor to view and change the Registry configuration.

After this lesson, you will be able to■

Identify the purpose of the Registry.

■

Define the hierarchical structure of the Registry.

■

View and edit the Registry by using Registry Editor.

Estimated lesson time: 40 minutes

What Is the Registry?

The Registry is a hierarchical database that contains a variety of different types of data,

including descriptions of the following:

■

The hardware installed on the computer, including the central processing unit

(CPU), bus type, pointing device or mouse, and keyboard.

■

Installed device drivers.

■

Installed applications.

■

Installed network protocols.

■

Network adapter card settings. Examples include the interrupt request (IRQ) num-

ber, memory base address, I/O port base address, I/O channel ready, and trans-

ceiver type.

The Registry structure provides a secure set of records. The data in the Registry is read,

updated, or modified by many of the Windows XP Professional components. Table 4-6

describes some of the components that access and store data in the Registry.

Table 4-6

Components That Use the Registry

Component Description

During startup, the Windows XP Professional kernel (NTOSKRNL.EXE)

Windows XP

Professional kernel

reads information from the Registry, including the device drivers to load

and the order in which they should be loaded. The kernel writes infor-

mation about itself to the Registry, such as the version number.

Device drivers Device drivers receive configuration parameters from the Registry. They

also write information to the Registry. A device driver informs the Regis-

try which system resources it is using, such as hardware interrupts or

direct memory access (DMA) channels. Device drivers also report discov-

ered configuration data.

User profiles Windows XP Professional creates and maintains user work environment

settings in a user profile. When a user logs on, the system caches the

profile in the Registry. Windows XP Professional first writes user configu-

ration changes to the Registry and then to the user profile.

Setup programs During setup of a hardware device or application, a setup program can

add new configuration data to the Registry. It can also query the Registry

to determine whether required components have been installed.

Hardware profiles Computers with two or more hardware configurations use hardware pro-

files. When Windows XP Professional starts, the user selects a hardware

profile, and Windows XP Professional configures the system accordingly.

NTDETECT.COM During system startup, NTDETECT.COM performs hardware detection.

This dynamic hardware configuration data is stored in the Registry.

The Hierarchical Structure of the Registry

The Registry is organized in a hierarchical structure similar to the hierarchical structure

of folders and files on a disk. Figure 4-2 shows the hierarchical structure of the Registry

as displayed by the Registry Editor.

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Figure 4-2

Registry Editor displays the hierarchical structure of the Registry.