Q: Can I install aR2 domain controller from media created from a SYSVOL backup of an earlier operating system?
A: Since Windows Server 2008 it has been possible to use Install From Media (IFM) to promote a server to a domain controller. With IFM the server gets most of the Active Directory (AD) directory information tree (DIT) and SYSVOL content and then uses normal replication from an online domain controller to catch up any changes since the media was created. The actual media used is generated on another domain controller and is essentially a backup of its system state. This system state backup can be created using ntdsutil ifm create full on a domain controller. (For additional options, see the Microsoft TechNet article "Installing AD DS from Media.")
It isn't possible to use the AD DIT from a previous version of Windows as the media source for a domain controller promotion using IFM; it must be the same version of Windows.