To activate this feature, create a new ExchangeConn DWORD value under the HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MessengerService\Policies registry subkey. Set ExchangeConn to 2 to allow only Exchange Server IM connections, to 1 if you want to allow MSN connections while keeping Exchange as the primary connection, or to 0 for the default connection to MSN first, then Exchange. The microsoft article "XFOR:How to Configure INstant Messaging Client System Policy Settings" (http://suport.microsoft.com/default.aspx?scid=kb;en-us;q264472) describes other settings you can tweak to control IM client behavior (including turning automatic updates on/off)