jOrgan should run flawlessly on Windows XP or Vista. Download the installer and start it with a mouse double click:
The installer for the Java Runtime on Windows is available in two flavors, online and offline. We recommend the offline installer available at http://www.java.com.
The program MIDI Yoke offers virtual MIDI devices that might be necessary to connect jOrgan to other MIDI programs.
MIDI-OX is a MIDI stream processor.
Some audio programs (e.g. software samplers) require an ASIO driver to be able to link their sound output to your sound card. The ASIO 4 All driver is fairly easy to install and use and has proven to work well with most sound cards.