There are a couple of things you have to do before you can manage your Windows Server 2008 (and R2) Servers. Windows Server 2012 starts with a new Server Manager that takes a little getting used to. It’s main purpose seems to be to act as a managing point for a bunch of servers. When you first integrate a new Windows Server 2012 machine into an existing 2008 Active Directory environment you will be met with many Red Flags and Refresh Errors. This can be solved by first installing Windows Management Framework 3.0 in all of your existing Windows Server 2008 and Server 2008 R2 servers. Windows Management Framework 3.0 includes PowerShell 3.0, WMI & WinRM, and is listed as KB2506146 or kb2506143.
However, installing WMF 3.0 is not enough, as you will still be met with “cannot get performance data” errors in Server Manager even after running winrm quickconfig on each of the 2008 servers. You then actually have to go and download Hotfix KB2682011 from Microsoft, and you will have to log in with a Microsoft Account and fill out a form from which they will use to email you a link to download the Hotfixes. You will have to choose between a Windows Vista and Windows Server 2008 R2/Windows 7 (6.0 and 6.1) packages to download.