A simple explanation how to remove an obsolete DFS namespace server from a Windows 2008/2008r2 Server.
Since Microsoft removed the Support tools with Windows 2008 and replaced them with RSAT, there is no need to install any tools anymore. Just a command and happiness.
dfsutil diag unmapdomroot \<domainname><DFSname> \<DFSrootserver><DFSshare>
Getting an error about:
Could not execute the command successfully SYSTEM ERROR - The system cannot find the file specified.