Hi all, ????????? Thanks for help last time, currently i am struck in UM-KM data passing, the problem is 1. I am able to pass the data from UM-KM 2. In KM-UM data passing i am facing the problem ?? a. in Read IRP if i dispatch the IRP_MJ_READ to the portcls the player and recorder are working correctly but i am not able to get the data from the buffer (IO_BUFFER) ?? b.If i complete the IRP here i am able to get the data from the KM-UM in the buffer but the player says that the driver is not able to play the audio.( I am completing the IRP with STATUS_SUCCESS, i tryed with PROCESSING_REQUIRED also it doesnot work) Can any one help me in this matter Thanks karthik SG