Microsoft released a whitepaper about P2V migration with Virtual Server Migration Toolkit (VSMT):
IT departments attempting to consolidate servers by using virtual machine technologies face a challenge when applications and operating systems do not readily migrate to a virtual machine environment. Manually reinstalling software in a virtual machine is both inefficient and costly. Frequently, this isn’t even an option as installation disks are misplaced and product keys are lost.
Microsoft Virtual Server Migration Toolkit (VSMT) is designed to help solve problems associated with migrating to Virtual Server 2005 by creating a reliable and repeatable process for migrating an operating system and installed applications from a physical server to a virtual machine.