Hi Brian, thanks a lot for your very thorough reply. Unfortunately much of your advice is beyond my capacity to do but I do have MIDI-Ox and when I run it and select the GXP88 as my midi input device, the program indicates that the driver is being used by a different program, and no midi data shows up in the MIDI-Ox monitor display. So, yes, everything indicates that some, for now unknown, application grabs the driver shortly after Windows boots. WHich brings me back to the question of how I can identify the culprit in order to do something about it.