With the official launch of Windows .NET Server (Win.NET Server) 2003 just around the corner, now might be the time to look at migration paths to the new OS. Six basic migration scenarios exist—three each for Windows 2000 Server and Windows NT Server 4.0. The three main roles for each of these OS versions are a file and printer server, a Web server, and an application server. When deciding whether to migrate, you need to consider both the OS version you're running and the role the OS fills.

Cases for Upgrading NT
Although Win2K Server has been around for more than 2 years, a lot of businesses still run NT as their primary network OS. Most of these installations likely are in small-to-midsized companies, in which the need for Win2K's and Active Directory's (AD's) enterprise-management capabilities aren't pronounced.

For the file- and printer-server scenario, the key reasons to upgrade NT to Win.NET Server are faster performance, better network infrastructure, and enhanced security. If your network runs well and its manageability and security are adequate, you don't really need to migrate. However, even if your hardware is running OK in your current environment, you need to consider whether you can recover from a disaster or a hardware failure if you don't migrate. Many hardware components that went into building NT systems 4 or 5 years ago are no longer available, and few things are as panic-inducing as finding out that you can no longer buy the tape drive that you need to restore your system. Furthermore, if you plan to upgrade your server hardware to improve performance, you should seriously think about jumping to Win.NET Server at the same time because NT doesn't support many of the new hardware devices that have become available in the past few years.

The same considerations apply if you're trying to decide whether to migrate an NT application server. Only a select group of applications really use AD. If your system doesn't run such an application and system performance is satisfactory, you don't need to migrate. But if you're looking to speed performance through new hardware or you want to improve network security, moving to Win.NET Server makes sense.

If you're using NT as a Web server, the considerations are a bit different. Microsoft Internet Information Services (IIS) 6.0 offers many security and reliability improvements over Internet Information Server (IIS) 4.0. And Win.NET Server eliminates much of the downtime associated with administrative tasks: Win.NET Server can perform on the fly more than 70 common functions, such as installing applications, that require a reboot in NT. Combining IIS 6.0 and Win.NET Server yields significant availability and reliability benefits.

Cases for Upgrading Win2K
The decision about whether to upgrade from Win2K Server is much tougher. Win2K has great hardware support and includes most of the AD and network infrastructure enhancements that Win.NET Server offers. Sites that now run Win2K Server as a basic file and printer server will realize few benefits from moving to Win.NET Server. One exception might be organizations that have highly distributed branch offices, in which Win.NET Server's AD deployment and replication enhancements would prove beneficial.

For Win2K application servers, the considerations are similar. Most installations will gain little benefit by moving to Win.NET Server. However, you might encounter an exception at the high end, where Win.NET Server could improve your application server's scalability and availability. Win.NET Server provides better out-of-the-box performance than Win2K and supports 64-bit hardware platforms and eight-node clustering.

In the Web server upgrade scenario, Win.NET Server offers clear advantages over Win2K. IIS 6.0 offers enhanced security, performance, and reliability compared to Internet Information Services (IIS) 5.0: IIS 6.0 is locked down by default, and Microsoft has removed the scripts that constituted a playground for intruders. Plus, a new response-queue architecture makes IIS 6.0 more reliable and more scalable.

Plan for the Future
If your NT environment is stable and performs well, you have no need to migrate. But if you want to replace aging hardware, consider jumping to Win.NET Server. For Win2K users, some new Win.NET Server features make sense in certain scenarios, but in most cases, migration offers little benefit. And whether you run Win2K or NT, IIS 6.0 makes Win.NET Server a better Web server.