Windows Vista : Automating Installation - Understanding Setup

The Windows Vista installation process is simple. All editions of Windows Vista use the same installation image (Install.wim in the Sources folder of the installation media). The product key determines which edition of Windows Vista installs. This simplifies the installation process and allows the use of one basic image to install all systems. The installation process is divided into three phases: Windows Preinstallation Environment (Windows PE), Online Configuration, and Windows Welcome.

Windows Setup runs in phases, which the following sections describe. These phases—Preinstallation Phase, Online Configuration Phase, and Windows Welcome Phase—occur in order and simply designate a point in the installation process. Windows Setup also has configuration passes (see the section “Setup Configuration Passes”). Each configuration pass performs a specific function and applies related settings from the Unattend.xml answer file.

You can customize the setup process at many phases through the use of answer files. The following list describes the answer files you use to customize the Windows Vista installation experience:

• Unattend.xml The generic name given to an answer file that controls most unattended installation actions and settings for most phases. When named Autounattend.xml and placed in the appropriate folder, this file can fully automate installations from the original Windows Vista media.

• SetupComplete.cmd While not actually an answer file, this file controls installation activity at the end of the online configuration phase. You can use it to copy files and settings or to install applications.

• oobe.xml oobe.xml is a content file you use to customize the out-of-box experience: Windows Welcome, Welcome Center, and ISP Signup.

Preinstallation Phase

During the preinstallation phase, Windows Setup loads and prepares the target system for installation. Figure 1 illustrates where this phase fits in the installation process.

Figure 1. Windows PE phase.

Tasks performed during this phase include:

• Windows Setup configuration Setup is configured by using either the Windows Setup dialog boxes (interactive) or an answer file (unattended). Windows Setup configurations include adding a product key and configuring a disk.

• Windows PE configuration Answer files settings are applied during the Windows PE configuration pass.

• Disk configuration The hard disk is prepared for image deployment. This might include partitioning and formatting the disk.

• Windows image file copy The Windows Vista image is copied to the disk from the distribution media or a network share. By default, the images is contained in Sources\Install.wim on the product media or distribution share.

• Prepare boot information The Windows Vista boot configuration is finalized. This includes configuring single- or multiboot configuration settings.

• Process answer file settings in the offlineServicing configuration pass Updates are applied to the Windows Vista image, and packages—including software fixes, language packs, and other security updates—are applied to it.

Online Configuration Phase

During this phase, Windows Vista performs customization tasks related to the computer’s identity. Figure 2 shows where this phase fits into the overall process.

Figure 2. Online Configuration phase.

The Specialize pass, which runs during this phase, creates and applies computer-specific information. For example, you can use an unattended setup answer file (Unattend.xml) to configure network settings, international settings, and domain information, as well as run installation programs. You can also copy files, install applications, and modify system configuration by supplying a custom SetupComplete.cmd file to be run during this phase.

During the Online Configuration Phase, you can use scripts to install applications and configure the destination computer. However, a task sequencer, which enables you to filter tasks based on conditions, such as whether or not a particular device is installed, is better suited to this purpose. A task sequencer also provides advanced features such as the ability to wait until a certain condition arises before continuing, and grouping tasks into folders and then filtering the entire group. The companion DVD includes a script-based task sequencer, Taskseq.wsf, that provides all these advanced features and more. It reads tasks sequences from .xml files and then executes them. The file Sample_Task_Sequences.zip includes sample task sequences that demonstrate how to build. Do not run these sample task sequences on production computers. Read the documentation included in the source code for more information about using Taskseq.wsf.

Windows Welcome Phase

In this phase, shown in Figure 3, the installation is finalized and any first-use customizations you want to apply are presented. You can customize the Windows Welcome screens and messages and store these customizations in an oobe.xml file.

Figure 3. Windows Welcome phase.

Setup Configuration Passes

Windows Setup makes several passes, and you can configure each pass by using an answer file. It is important to understand what is happening at each pass to be able to configure settings and the place the settings at appropriate pass. Table 1 lists the passes and describes what happens during each one.

You can apply some settings at more than one pass. For example, IP settings would apply during the Windows PE pass to allow network access to access image files, and also at the specialize pass to configure the IP settings for the new operating system.