As announced when Virtual PC 2004 was set free, Microsoft is now also offering free downloads of Microsoft Virtual PC 2007.
Use Microsoft Virtual PC 2007 to run multiple operating systems at the same time on the same physical computer. Switch between virtual machines with the click of a button. Use virtual machines to run legacy applications, provide support, train users, and enhance quality assurance.
Check Microsoft for more information and a link to download Virtual PC 2007.