Windows System Image Manager – Overview

Before you start

Objectives: learn what is Windows SIM, what is Windows setup, what are answer files and how we can use them, and which installation phases can we edit using Windows SIM.

Prerequisites: you should be familiar with general automated Windows installation concepts.

Key terms: installation phases, windows sim, answer file, configuration pass


Windows Setup

Windows Setup is the program that controls the Windows installation process. We can run Windows Setup using the Interactive (attended) or Automated (unattended) method. Using the interactive method we install Windows on a single computer by inserting the installation medium and manually starting the setup program. During the setup process, the user responds to prompts on the screen to customize the Windows installation. Interactive setup is typically used by end users to install Windows. Interactive setup can also be used during image preparation to install and configure Windows on the source computer.

With an automated installation, the installation program runs with little or no user intervention. Automated installations use an answer file to provide answers to the prompts during Windows Setup. When setup finds the necessary information in the answer file, the on-screen prompt is skipped (not displayed). If the answer file does not contain a needed response, the installation pauses and waits for user input. Automated installations require up-front planning and configuration, but reduce the overall time and effort for installing Windows. Answer files can be used to install Windows on the source computer prior to image capture, or to control the installation of images on target computers.

Windows SIM

Window System Image Manager or Windows SIM is a tool which we can use to create an answer file for Windows installation. An answer file is an XML-based file that contains the responses to prompts that appear during Windows installation, all without user interaction. Windows SIM uses installation within a Windows Image or WIM file and the Catalog file to display the available components that can be customized and configured trough answer file.

Answer Files

We can use Win Sim to create an answer file that includes the basic Windows Setup configuration, modify the answer file’s settings to change how Windows will be installed, add or remove custom drivers or add applications. We can also add actions to be performed during the various configuration passes of the installation process. After creating the answer file we should validate the file in Windows SIM. After validation we can save the answer file (in XML format). The recommended name for the answer file is Autounattend.xml or Unattend.xml. Before starting Windows Setup we should save the answer file to a location that will be accessible during the installation such as a removable media or the network installation share. When Windows Setup starts, it will automatically search for an answer in the same directory as the Windows Setup program and root directory of removable storage devices. For example, if we are installing Windows from a network share, we should copy the answer file to the share in the same directory as the setup program. If we are installing Windows from the installation disc, we should copy the installation file to a removable drive and insert the drive before starting the setup program. The computer has to boot from the installation disc, not the removable device.

We can start setup using an answer file with a non-default name or in a non-default location by using the /unattend switch to identify the path and name of the answer file. For example, use the following command to use a custom file located on the F: drive:

setup.exe /unattend:F:win7installAnswers.xml

A single answer file can be used during all installation phases. Also, instead of using a single answer file for the entire installation, we can create separate answer files to be used at different stages of the installation process. Using different answer files could be useful during image preparation and deployment.

Windows Installation Phases

Windows installation is divided into several phases, with each phase being called a configuration pass. We can use Windows SIM to edit each installation phase.

Windows PE Phase

The first installation phase is the Windows PE (Pre-installation Environment). This phase can be used to configure Windows PE options and basic Windows setup options. These options can be, for example, setting the product key and configuring the hard disk configuration. In this phase we can also add drivers to the Windows PE driver store for accessing hard drives and network devices are not natively supported by Windows PE. Windows PE also creates WinPE logs or the page file.

In this phase the Windows Setup program starts. In the setup the operating system edition to install is identified, the product key is entered, the hard disk is partitioned and formatted and the Windows image is copied to the hard disk.

OfflineServicing Phase

After the image file is copied to the computer, the offlineServicing configuration pass runs. The offlineServicing phase allows us to apply updates, software packages, language packs and security updates to Windows Image. During this phase we can also add drivers to the image that will be used after the installation. This pass runs after the image is copied to the computer and before the computer reboots.

Specialize Phase

After the computer reboots, the specialize pass runs and customizes the computer based on the specific computer hardware. In the Specialize phase system specific information is configured, such as network settings, computer name and domain information. A unique security identifier (SID) is also assigned.

OOBE System Phase

The oobeSystem configuration pass runs after the specialize pass and configures Windows settings prior to the Windows Welcome screen showing. This phase happens before the end user logs in for the first time. In this phase initial user accounts are created, Windows Shell options are configured, language and local settings are identified. After the oobeSystem pass runs the installation process is complete.

The following additional configuration passes can run if we specifically configure the setup program to run them.

Generalize Phase

The generalize pass prepares a system image for deployment to multiple computers by removing computer-specific information from the existing Windows installation such as Security Identifier (SID), logs, restore points and hardware specific information. We must run this phase if we want to transfer the installation to different computer. It runs after the offlineServicing pass and before the specialize pass.

Audit System Phase

The auditSystem pass adds system configuration information to an image that has been installed on a computer. Audit System phase enables a computer to start in Audit mode instead of Welcome mode. It runs immediately after the specialize pass and before user logon. In audit mode we can add additional drivers, applications and test our installation. When we start the computer in Audit mode, oobeSystem tasks are not performed. Audit mode is used to customize an image before it is captured by loading additional drivers or installing applications. Audit mode is also used after an image has been installed on the target computer to customize the specific computer or add applications used by the computer’s user. This phase allows customization while Windows is running in the system context before a user logs on to the computer.

Audit User Phase

The auditUser pass runs when the computer starts in auditing mode after the user logs on. This pass runs after the auditSystem pass. The Audit User phase allows customization if we are in the audit mode, but allows it after the user logs on to the computer in audit mode.

After the auditUser pass runs, the computer will continue to restart in Audit mode and will not enter oobeSystem mode until Audit mode is disabled.

Remember

Windows Setup is the program that controls the Windows installation process. Window System Image Manager or Windows SIM is a tool which we can use to create an answer file for Windows installation. An answer file is an XML-based file that contains the responses to prompts that appear during Windows installation. The recommended name for the answer file is Autounattend.xml. Windows installation is divided into several phases, with each phase being called a configuration pass. We can use Windows SIM to edit each installation phase.