Deployment Strategies

The two basic approaches to automating Windows deployment are unattended or image-based installation.

Unattended installation. Unattended installation (often called “scripted installation”) uses the normal Windows setup program, but with an answer file to supply any input to the process. Advantages of this approach include the fact that an administrator or user does not have to monitor the installation, the installation is quicker (the process never stops to wait for user response) and the fact that the answer file ensures consistent responses to all setup requests for input. The disadvantage is that the lengthy full setup still runs, albeit faster than if user interaction is required.

Image-based installation. Image-based installation takes a master computer and clones its hard drive image to any number of similarly configured computers. Advantages include fast, consistent installation. The disadvantage is that Windows does not lend itself to creating a master for copying-the master image often “tattoos” or permanently writes user personalization and hardware-specific information to the Registry and other locations on the computer. Therefore, creating a master image for duplication involves stripping all such information, such as the unique Security Identifier (SID), from the master and generating a unique value for each clone created from the master’s image. In addition, not all services lend themselves to imaging. Services such as Active Directory (AD), clustering, certificate services, and file servers using the Encrypting File System (EFS) cannot be imaged. Instead, alternative methods must be used. In the case of AD, for example, the base server can be deployed using an image, and then the AD installation program (DCPromo) can be called automatically by a script to complete the configuration.