Microsoft Assessment and Planning Toolkit - Part 1
I find this tool very useful with in the Deployment arena, it has the
capability provide inventory and assessment without requiring an agent
software on any computer in your network thus simplifying your planning
process for migrating your laptops, desktops, and servers to Windows 7,
Windows Server 2008 R2, Windows Server 2008, Windows Vista and
Microsoft Office 2007
..... more: link here