Major migration projects make a test lab practically mandatory. A test environment allows you to try new things without risk; it also helps you write and test your migration plan.
It's best to build a lab that mimics your production environment as closely as possible. Seeing your company's directory structure in Active Directory (AD), for example, gives you a "been there, done that" confidence that no canned environment can duplicate.
Here's how to build a system that serves as the cornerstone of a lab network. You can use this lab for planning and practicing migrations from Exchange 5.5 to Exchange 2000 and/or from Windows NT 4.0 to Windows 2000.
Your test server should have the capacity to run Windows 2000 AD and Exchange 2000. It also needs enough disk space to restore your Exchange directory and information store and a tape drive to perform the restore.
Follow these steps:
You now have a test server with your company's production Windows NT 4.0 and Exchange 5.5 directories. Now that you've built the main server as a PDC, you can add other systems into the environment as required to simulate your production network.