1. Run and configure MyOrgan for your sound and midi interfaces
a. If you don't have an ASIO driver for your sound card I suggest you get hold of ASIO4ALL [http://www.asio4all.com/] and install it first, and then select "ASIO: ASIO4ALL v2" in the 'Sound output device' drop-down.
b. Select your MIDI Keyboard interfaces in the 'Midi input devices' column.
c. I use MyOrgan with all the enhancements checked.
d. Click on the MIDI messages tab and see what channels Manual 1 (Pedal), Manual 2 (Great), and Manual 3 (Swell) are configured to. Change these channels to your MIDI setup [if this is confusing - just post another question here and we'll explain
2. Load the Stiehr-Mockers Jeux d'orgues 2 MyOrgan sample set into MyOrgan by clicking on 'File' -> 'Open' [then navigate to where the sample set has been decompressed] -> click on the stiehrextc30a.organ file (you might not see the '.organ' file extension if you have not enabled Windows to display file extensions). MyOrgan will then show that it is loading all the wave files.
3. Once MyOrgan has finished loading the samples,click on the stop tabs that you want to hear, and play your MIDI keyboard. The manual on the screen should show a red outline for each note played, and you should hear the sound of the pipe playing.
Hope this helps,
Johannesburg, South Africa