Troubleshooter--Upgrading Exchange 5.5/E Hardware

What's the best way to upgrade the hardware platform for my Exchange Server 5.5, Enterprise Edition (Exchange 5.5/E) machine? It's the only email server in my enterprise, and I want to keep the same machine name and IP address.

You can upgrade in several ways. On the easy end of the spectrum, you can use the famous Ed Crowley Server Move Method. (See http://www.exchangefaq.org/managing/0007.php3 for an explanation of this method.) This approach requires you to bring up your new hardware with a different NetBIOS name and IP address; of course, you can easily change the IP address later. If you absolutely must keep the same NetBIOS name, you can back up your server thoroughly, then perform a disaster recovery to the new box. For help with this method, see Microsoft's excellent disaster-recovery white papers at http://www.microsoft.com/exchange.