Windows client issues
The client machines must be reconfigured as well. In a Windows NT Server environment, the clients are usually configured with the IP addresses of both a WINS server and a DNS server. In such an environment, the WINS server is typically used for name resolution on the local network and the DNS server is used by the company's ISP for Internet name resolutions. When your client makes the upgrade to Windows 2000, you'll have to remove the references to the WINS servers from the clients and configure the machines to point to a local DNS server rather than to an Internet-based DNS server. This means the Windows client machines won't be able to surf the Internet unless you also configure the local DNS server to forward unresolved requests to the ISP's DNS server. Will the client machine benefit?
Active Directory has some great features that are targeted toward clients, such as the ability to enforce security through group policies and to automatically distribute software to the clients. The problem is that not all clients can take advantage of such features. All Windows clients are capable of logging into a Windows 2000 domain and accessing shared resources such as files and printers. But only clients that are Active Directory-aware can take advantage of things like group policies and automatic software distribution. This means that unless the client machines are running Windows 2000 or Windows XP, they won't be able to use Active Directory to its full potential. There is an Active Directory extension available for Windows NT 4.0 and Windows 98. However, these extensions are very limited in scope and won't allow the machine to take advantage of most Active Directory features. Can't see the forest for all the trees
One final reason for holding off recommending an upgrade to Active Directory is the time it takes to plan your client's server architecture. As I said, the Active Directory model is nothing like the Windows NT domain model. In Windows NT, servers were organised into domains. Each domain was an independent entity, but domains could be configured to trust each other and share resources. In Windows 2000, the domain model still exists, but the domains are organised into tree structures. This means that there can be parent and child domains. The domain trees are collectively part of a forest in which each domain trusts every other domain. Because of the way domains work in Windows 2000 and the addition of two new structural components (organisational units and sites), there are now lots of different ways to build a network. You can organise a network geographically, by department, by both geography and job function, or any of a zillion other ways. While the ability to organise your client's network in so many ways gives you great flexibility, some organisational methods are much more efficient than others. And what works well in one organisation won't necessarily work very well in another. So it isn't a good idea to implement Active Directory on a whim. Take the time to really understand your client's needs before you begin making changes.