On Windows 2008 R2 you can only install FCS agent, FCS server components are not supported.
see here for more info
http://technet.microsoft.com/en-us/library/bb404245.aspx
Bechir Gharbi. MCSA, MCSE M+S, MCITP Server/Enterprise Administrator, MCT, MCTS Configuration Manager/Forefront (Time Zone : GMT+1)