Selecting a Migration Path

Before you migrate your environment from Windows NT 4.0 to Windows Server 2003, you must select the migration path the best meets the needs of your organization. The size of your organization, your existing hardware, and the operating system that you are currently running impact the migration path that you select.

Organizations that include fewer than 75 network devices might want to consider using the Microsoft Small Business Server network operating system Small Business Server network operating system instead of Windows Server 2003. Small Business Server delivers e-mail, secure Internet connectivity, business intranets , remote connectivity, support for mobile devices, and file and printer sharing on a single server.

For more information about migrating to Small Business Server, see the Small Business Server Web site at http://www.microsoft.com.

Evaluate Your Existing Hardware

If you have any domain controller in your current environment that is capable of running Windows Server 2003, then plan to upgrade this domain controller in place to establish your Windows Server 2003 Active Directory domain. To do this, the domain controller must be the PDC; if it is not currently the PDC, you must promote it to be the PDC before you upgrade.

Evaluate your existing hardware to identify which servers you can upgrade to Windows Server 2003 and which servers do not meet the recommended hardware requirements. To do this, first document the RAM, CPU, and disk space on each server in your environment, and then compare this information to the Windows Server 2003 System Requirements link on the Web Resources page at http://www.microsoft.com/windows/reskits/webresources.

Based on this evaluation, determine whether you need to purchase new server hardware.

Table 1.1 shows the server hardware configuration information for Fabrikam, Inc.

Table 1.1: Fabrikam Server Hardware Configuration
Existing Server	Operating System	RAM	CPU	Disk Space	Upgradeable to Windows Server 2003 Domain Controller?	Upgradeable to Windows Server 2003 Member Server?
SEA-FAB- DC01	Windows NT 4.0	2 GB	1 x 850 MHz	10 GB	Yes	Yes
SEA-FAB- DC02	Windows NT 4.0	256 MB	1 x 400 MHz	4 GB	No	Yes
SEA-FAB- MS01	Windows NT 4.0	256 MB	1 x 400 MHz	2 GB	No	No

The PDC, SEA-FAB-DC01, meets the requirements for a Windows Server 2003 “based domain controller, so it will be upgraded in place.

The BDC, SEA-FAB-DC02, does not meet the recommended requirements for a Windows Server 2003 “based domain controller. Fabrikam will use it as the Windows NT 4.0 rollback server if a problem occurs during the in-place upgrade process. Because two domain controllers at minimum are required, they will plan to deploy a new computer, SEA-FAB-DC03, as a domain controller running Windows Server 2003.

The member server, SEA-FAB-MS01, does not meet the recommended hardware requirements for a member server. The services running on this server will be migrated to SEA-FAB-DC03, and SEA-FAB-MS01 will be retired . Fabrikam s new environment will consist of two servers, SEA-FAB-DC01 and SEA-FAB-DC03.

If the server that holds the PDC role in your environment does not meet the hardware requirements, you can transfer the PDC role to a BDC that does meet the hardware requirements and upgrade the new PDC to Windows Server 2003. If none of your Windows NT 4.0 domain controllers meet the Windows Server 2003 hardware requirements, in order to upgrade in place, you must install a Windows NT 4.0 BDC on a computer that does meet the hardware requirements for a domain controller that is running Windows Server 2003 and transfer the PDC role to it.

You can also add a Windows Server 2003 “based member server to a Windows NT 4.0 domain at any time before you upgrade to Windows Server 2003 Active Directory. Windows Server 2003 “based member servers can operate within a Windows NT 4.0 environment. However, you cannot install Active Directory on the member server to make it a domain controller, until after you have upgraded the Windows NT 4.0 PDC.

If the PDC is running other services, such as WINS, DHCP, file and print, or Web server, you must also determine whether to upgrade those services in place or migrate them to other servers before upgrading the PDC. If the PDC is running Remote Access Service, you must migrate the service to a server running Windows Server 2003 before you upgrade the PDC. For more information about assigning server roles to server hardware, see Assigning Server Roles later in this chapter.

Figure 1.2 summarizes the process for evaluating your current hardware to determine which server, if any, in your current environment you will upgrade to Windows Server 2003 to establish your new Windows Server 2003 domain.

Figure 1.2: Evaluating Your Existing Hardware

Determine Supported Operating System Upgrades

Identify the Windows NT 4.0 platforms that are running in your environment and determine whether an operating system upgrade to Windows Server 2003 is supported, or whether you must perform a clean operating system installation.

You can upgrade the following Windows NT 4.0 platforms to Windows Server 2003, Standard Edition directly:

Windows NT 4.0 Server, Standard Edition
Windows NT 4.0 Terminal Server

Important
All versions of Windows NT 4.0 must have Service Pack 5 or later installed before you upgrade to Windows Server 2003.

You do not need to reinstall applications on platforms that you can upgrade directly to Windows Server 2003; however, be sure to verify with the vendor of the application that it can run on Windows Server 2003.

If you have computers in your environment that are running operating systems that you cannot upgrade directly to Windows Server 2003, such as the Microsoft Windows NT 3.51 operating system, you must do one of the following:

If you need to retain applications that are located on those computers, verify that those applications will function on and are supported by Windows Server 2003, and then upgrade the computers to run an operating system that you can upgrade to Windows Server 2003.
If you do not need to retain applications that are located on those computers, perform a clean installation of Windows Server 2003 on those computers.