Jokeyman123, thank you. I had some success downloading the 64-bit version from that link you gave. After installing the driver, I added my PX-410R keyboard to Studio One External Devices, and recorded some MIDI. This is a big breakthrough!
Next question: I would like to record/playback the keyboard to/from the DAW, as a wav file, or similar audio file. I have the Casio manual, which says go to http://music.casio.com. I'm looking for data management software, and have found SMF converter (see attachment) - is this what I need?
RoJoe