Are you familiar with the Microsoft Assessment and Planning Solution Accelerator (MAP)? If you’re not, you might want to be. From the resources library:
“MAP (download) is a powerful inventory, assessment, and reporting tool that can securely run in small or large IT environments without requiring the installation of agent software on any computers or devices. The data and analysis provided by this Solution Accelerator can significantly simplify the planning process for migrating to Windows Vista, Microsoft Office 2007, Windows Server 2008, Microsoft Application Virtualization (formerly SoftGrid), and Windows Server virtualization technologies including Virtual Server 2005 R2 and Windows Server 2008 Hyper-V.”
As Virtualization.info points out, Microsoft doesn’t seem to put much effort into making the tool known by the rest of the world. The tool could however be useful, and comes at a great price considering its feature list; it’s completely free!