Thanks for the fast response. What you said made sense. There is a lot of groping around using half knowledge when getting to grips with new technologies and I was not at all clear what the service name was doing. I tried substituting the serial port service guid as you suggested. I am still getting...

BluetoothEndPoint ep = null ; ep = new BluetoothEndPoint ( this .m_Bdi.DeviceAddress, BluetoothService .ObexFileTransfer); this .m_BtClient.Connect(ep); hi there how can i set the application pin number by code and not by the bt window program?????? 10X