Since Microsoft’s acquisition of Softricity in 2006, application virtualization has developed mainstream credibility as a mechanism for delivering applications.  Initially, it was also branded as a solution to application compatibility issues; however, with few exceptions, this has generally not been the case.  Applications, even when virtualized, interact with the operating system.  Therefore, any incompatibilities that exist with the OS will persist after virtualization.  That said, there are many advantages to virtualizing applications in terms of deployment, portability and stability, and a variety of vendors provide solutions in this space.

Given that the migration process to a new OS such as Windows 7 typically involves a touch on all applications, it represents an opportunity to take advantage of a virtualization solution while preparing the applications for the new OS.  Application virtualization requires a number of constraints and the skills to handle applications through the process are relatively scarce, so it’s important to have an understanding of how many applications are suitable for it, and which ones.  Planning for the inclusion of application virtualization is worthwhile, but it should be viewed for what it is: an additional stream of work through the migration process.  Like any incremental effort, the ultimate benefits must be weighed against the investment required to achieve them.

An OS is a complex software foundation, and Windows 7 is no exception.  It’s responsible not only for delivering applications, but also for managing and securing an organization’s data and systems.  The configuration of the OS requires a variety of decisions relating to the inclusion of core applications, group policy objects, file and registry permissions and other settings.

In addition to the ‘base image’ configuration, additional consideration is required for the provision of hardware specific drivers and add-ons.  Windows Vista introduced a modular build system to address the long-standing objective of IT administrators to maintain a single OS image for multiple hardware types that can be modified at deployment time to include specific drivers.

A number of application compatibility issues also may be mitigated by including deprecated components or modifying default settings within the OS configuration.  When planning a Windows 7 migration, it’s helpful to gain an understanding of how many applications in the portfolio have, for example, interactive services, legacy help files or dependencies on legacy language runtimes.  This can allow compatibility remediation to be bundled into the OS build process rather than on a time-consuming, per-application basis.