Recently, I upgraded both of our domain controllers to Windows Server 2012 R2. Before I did that, one of them was running Windows Server 2008 R2 and the other Windows Server 2008. Our domain is currently running at Functional Level 2003; I don't know why it wasn't at least raised to 2008. Anyway, I'm looking for some advice and feedback about raising the functional level to 2012 R2. What would the impact be? Would I expect any detrimental side-effects? Can I raise it from 2003 to 2012 R2, or do I need to take add a middle step in there and raise it first to 2008 or 2008 R2? Any help would be appreciated. Thanks.