My environment is Win2008 R2 SP1. I have NCO3 downloaded and my example works (i.e. I can connect to SAP etc.) if have my own class defined for IDestinationConfiguration, and specify the Configuration Parameters. However, when I try to define the config. parameters via App.Config, I get the error at the "RfcDestinationManager" line - with the error message shown here http://www.dataxstream.com/2012/09/nco-3-cannot-get-destination-no-destination-configuration-registered/ Private _ecc As RfcDestination _ecc=RfcDestinationManager .GetDestination( "DEV" ) I do have SAPNCO.DLL and SAPNCO_utils.DLL reference with "Copy to local folder" = True. And I also copied the DLLs to to GAC just in case. Please comment. http://www.dataxstream.com/2012/09/nco-3-cannot-get-destination-no-destination-configuration-registered/