When installing vCenter Server 5.1u1b on Windows Server 2012 it uses ocsetup.exe (Windows Optional Component Setup) to install ADAM which works quite well. However, it does note OCSETUP has been depreciated and the scripts should be using DISM.exe
In Windows Server 2012R2 OCSETUP.exe has been removed. Hopefully this issue is resolved with vCenter Server 5.5 running on Windows Server 2012R2.
Windows Server 2012R2 retail version is available on TechNet.