Usually this means that the server side of the SCC interface is not installed properly.
To check this, open the registry editor and check the key HKEY_LOCAL_MACHINE\SOFTWARE\SourceCodeControlProvider\InstalledSCCProviders. If there are no subkeys, it is not installed [properly].
If it is, check where this key refers to, and be sure the file path given there is valid.
Hope this helps,
Dan