For those of you holding or pursuing CISSP certification, you should be familiar with the concept of change management as it relates to operational security. One of the primary goals of change management is to prevent changes to an environment from reducing security. Another important aspect of change management is the ability to roll back changes if they are determined after-the-fact to have a detrimental effect.

I'm sure we can all agree that being able to reverse changes is a good thing. However, there are numerous necessary configuration activities within Windows 2000, specifically dealing with Active Directory, that are permanent and irreversible.

This tip serves as a reminder and a warning. Make sure you understand what you are doing before you do it. If you are not careful, you may find yourself at the end of a one-way street with nowhere to go.

One of the best-known dead-ends is the migration of an Active Directory domain from mixed mode to native mode. This is an activity that should not be considered lightly. If you initiate this transformation, your domain will forever be restricted to Windows 2000+ servers as domain controllers. You will no longer be able to use Windows NT 4.0 servers as domain controllers. With over 60% of the private and government organizations still relying upon Windows NT, this is a trip you probably don't want to take.

Domain naming is irreversible, too. Once a domain is named, it must be destroyed and rebuilt in order to rename it. Make sure you plan out your naming scheme and inter-forest domain relationships before you start implementing. There is no easy way to correct mistakes.

Many network services, native applications and third-party software employ installations that cannot be undone. If you are not certain that you want a specific application or service to be present on a system throughout its lifetime, you should think twice about installing it temporarily on important systems. I recommend testing the uninstallation capabilities of desired products before putting them onto production systems.

James Michael Stewart is a partner and researcher for ITinfopros, a technology-focused writing and training organization.