Interface problem EVAL-AD5791SDZ + EVAL-SDP-CS1Z to PC

Hi,

I have connected  EVAL-AD5791SDZ + EVAL-SDP-CS1Z   to PC via USB port.  But when I run the evaluation software I get the message below.

"Error 1172 occurred at Invoke Node System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation.
Inner Exception: sdpApi1.SdpException: no connection made" 

I have ignored this error message and proceed with setting  the register values in software but EVAL-AD5791SDZ is not showing any output voltage.

The green and orange LEDs on the board is lit.

SDP-S driver is showing under ADI Development Tools in the Device Manager of windows 7.

Please help.

Thanks and Regards

Ittoop