When you try to install vCM on Server 2012 R2, you are unable to install SQLXML. SQLXML is a prerequisite to installing vCM on Server 2012, so this can be a problem. Also, if you download and install SQLXML manually, it doesn’t work.
To fix this and install SQLXML on Server 2012 R2 (which then allows you to install vCM), you need to first install .NET 3.5 Framework. After installing the .NET 3.5 Framework, you will then be able to install SQLXML and then vCM.