The traditional desktop computing model, as shown in Fig. 1, has
been one where the operating system, applications, and user data
and settings are bonded to a single computer. We will buy a
computer either with OS and some applications pre-installed, or
apply a hard disk image with targeted OS and selected
applications to the computer hardware. Once a computer is
deployed, a user can then log in the system, customize the
environment, run applications, change settings, create data and
files. This model is straightforward and easy to understand.
With respect to desktop deployment, this means that the OS,
application execution/presentation and user data are all self-
contained within a single device. This model has the advantage
of simplicity because it leverages well understood technologies
that ship with Windows. In addition, because a PC with this
model is configured to be completely self-sufficient, this
solution is well-suited to mobile use. However, the tight
binding between the various layers may not be a