History Software Assurance was part of Licensing 6.0 and initially only provided upgrades, but around the time of the Microsoft Office 2003 release, more benefits were added. In March 2006, Microsoft added Windows Vista Enterprise Edition and Windows Fundamentals for Legacy PCs. In June 2011 Microsoft added Windows Thin PC, a desktop virtualization application that allows locked down versions of Windows 7 to run on older hardware. References External links Microsoft Software Assurance home page An Independent View of Microsoft Software License Agreements, Network World, November, 2010 Top 75 Microsoft Licensing Terms – A Glossary From A(ntigen) To Z(une) Microsoft initiatives Software maintenance