Upgrades vs. Clean Installs
Microsoft supports two methods of installing Windows 2000
Professional on target workstations: through upgrading or clean
installs. Upgrading to Windows 2000 Professional implies that the
target workstation already has an existing operating system that
may have its own settings and configuration. If the target workstation
is configured with an operating system that is supported for
upgrading (see Figure 1.1 in the following section), then the setup
program can be instructed to upgrade in place, migrating all user
settings and applications available.
If, however, the target workstation is a new machine, requires
reinstallation, or is configured with a non-supported operating system,
then a clean installation must be applied to the workstation. The
primary drive of the target workstation is then installed with Windows
2000 Professional without searching for existing data (though data
can be preserved), applications, or configuration settings.
Administrators and support engineers should take the time to
perform the upgrade and installation process numerous times to be
aware of potential problems. Identifying show-stopping problems,
such as that the application does not work, may be a great deal easier
than handling issues (such as the profile directory has changed
to the Documents and Settings folder) that manifest much more
subtly.
Several factors will influence your decision whether to upgrade
or to apply a clean installation of Windows 2000 Professional. These
include:
 Current workstation management levels If modifications
to the workstation’s operating system and applications have
followed strict change controls, then the current state of the
workstation will be well known. An upgrade would best suit
a well-managed environment, preserving the investment in
your configuration information. If the state of the
workstations is indeterminate, then a clean install of
Windows 2000 Professional would allow you to revert the
configuration of the workstations back to a known state.
 User preferences and settings If your users have a level of
control over their workstations, they may have personalized
certain settings and preferences. It can be difficult to
determine what settings exist. To preserve these settings the
best option would be to perform an upgrade.
 Applications and data Some users may store data on their
local workstations, or install applications locally. An upgrade
would be the best choice to prevent inadvertently deleting
data, and would also ensure that applications would still
function (if compatible with Windows 2000 Professional).
Many businesses store data centrally for backup and
management purposes and as a result, a clean install could
be considered.
 Existing operating systems on client workstations The
installation type you choose will also be dictated by the
operating system of the client (see Figure 1.1) prior to
deployment. If, for example, you are using Windows 3.1, the
only option available would be to perform a clean
installation. Upgrading from previous versions of Windows
NT (version 3.51 and later) is inherently easier than
upgrading from Windows 9x. This is due to the commonality
between the operating system kernel architecture, device
driver models, registry database, security architecture, and
file systems. Upgrading from existing Windows 9x
installations can present additional issues to be resolved.
 Operating system history If your client workstations have
been through a regular cycle of upgrades, the preferred
option would be to perform a clean install, thus resolving
possible legacy issues. Migrating the workstation to
Windows 2000 Professional from a platform that has been
repeatedly upgraded could negate some of the advantages
(such as stability) of deploying Windows 2000 Professional in
the first place.
There are a number of ways to start the Windows 2000
Professional setup process. The setup or upgrade process can be
initiated by executing Winnt32.exe from a command line on a host
operating system that is compliant with the upgrade paths in
Figure 1.1 (Windows 3.51 Workstation or greater, and Windows 9x).
The setup executable, Winnt32.exe, is found in the i386 directory on
the Windows Professional CD-ROM. It is also possible to execute
setup from a bootable CD-ROM containing the relevant installation
files. Other solutions include using a network management application
such as Microsoft’s Systems Management Server (SMS), or a
bootable floppy disk with network drivers and a connection to the
Windows 2000 Professional installation source.
When using the setup program Winnt32.exe to install Windows
2000 Professional, the command lines used to initiate an automated
installation are very similar in all methods. Winnt.exe is used when
starting setup from 16-bit Microsoft operating systems such as
when using a bootable floppy disk.