Understanding Windows 7 Setup Process

In comparison to Windows XP, there are numerous differences in the deployment technologies that are now available with Windows 7 as new and improved tools have been developed based on technologies that were first introduced with Windows Vista. Before Windows Vista was released, Microsoft did not have robust tools to facilitate mass deployment. If you are unfamiliar with Windows Vista or your organization passed on it altogether, you might as well unlearn everything you know on Windows XP deployment and start from scratch.

Before we are able to prepare for volume deployments of Windows 7, it is important to understand the underlying processes of the installation so that we make the best use of the tools. There have been significant changes to the way the Windows operating system is now deployed. Let us first glance at the following list of things that have changed in deploying Windows since the Windows XP days:

» Booting up the Windows installation occurs through the Windows preinstallation environment (Windows PE), which replaces any DOS-based boot disk/media.

» Windows Setup is now a file-based image deployment.

» Installation source files may be 2 GB or higher.

» All Windows installations need to be activated.

» The Boot.ini is no longer used for boot configuration.

» Setup.exe is now the new command that launches the Windows installation process, replacing winnt32.exe.

» The Windows installation is independent from the Hardware Abstraction Layer (HAL.dll).

» Windows 7 is not language specific, whereas for Windows XP/2003 or earlier each language had its own build of the operating system. Languages are now separate packages.

» The Windows 7 DVD contains the source Windows Image (WIM) file containing all of the editions of this operating system’s version. The installer determines which product to install based on the license key.

The Windows 7 installation is now conducted through file-based images. What comes to mind when we talk about “imaging” is what in the industry is more commonly known as sector-based imaging. Numerous administrators have probably worked with third-party utilities for imaging such as Symantec Ghost (http://www.symantec.com/norton/ghost) or Acronis TrueImage (http://www.acronis.com/enterprise/) to take snapshots of a system volume in order to capture the desired system state and installation. The images these products capture are different from the WIM file format that is file-based. The main difference is that sector-based images copy indiscriminately sector-by-sector at a low level from a hard drive to build a snapshot of storage volume; file-based images such as WIM images are captured by taking snapshots at a higher level of files and folders. The bottom line is that even though sector-based images are very flexible because they can ignore the type of file system in use, they are somewhat unpractical to maintain and manage; in order to modify and edit a sector-based image, it would require deploying the image, making the changes, and recapturing it. In the case of WIM files, the action to modify and update the images can be performed by instantly “mounting” the captured image, applying the changes at the file system level, and then committing the changes immediately.

The image-based Windows setup process that was first introduced with Windows
Vista greatly facilitates the deployment of the operating system to disparate hardware architectures without requiring building separate installation packages/images. This same behavior can also be found in Windows 7, and it may come as good news to some administrators who did not have much exposure or were unable to deploy Vista. The way the new Windows 7 setup is designed streamlines many portions of previous operating system installations that would usually encounter obstacles when being deployed, especially from captured images.

There were many limitations when Windows XP images were deployed as these would not necessarily restore successfully on to any computer with a hardware architecture different than that of the system from which the image was captured. This created a lot of additional work for system administrators, including managing multiple images and developing custom scripts to force things to work properly. Important system components such as the HAL were tied to the specific installation device and would usually require additional steps/tools to allow a restored image to be reconfigured properly. Some of the known issues for Windows XP images include the following:

» The imaged computer is expected to boot from the same storage controller as the reference computer.

» The imaged systems need to use the same HAL as the reference computer.

» The sector-based imaging process is destructive; thus, it replaces all contents of the destination computer and could complicate some Windows deployment scenarios including in-place upgrades and other types of migrations.

» Maintaining the image to include updates and new applications was time consuming as directly modifying the image was not possible.

» The need for third-party imaging utilities that incurred additional licensing, training, and operational costs.

Windows 7 has several editions; however, all editions of Windows 7 use the same installation image (install.wim which may be found in the Sources folder of the installation media). What varies is that Microsoft packaged media that is specific to one edition, which means that if the setup is executed image from which the setup is based. Depending on the need of a particular system/user, the deployed OS can be any of the needed editions, and it will be installed without the need for additional source files. normally, it will allow the installation of just the edition that was purchased through the user interface; nevertheless, by using the unattended setup answer file (unattend.xml), it is possible to install any edition (provided that there is a license key available). By knowing this it is easier to understand that despite the many flavors of Windows 7, there is a universal

Source of Information : Syngress Microsoft Windows 7 Administrators Reference Jun 2010