I cannot give a certain answer to your question, since the choice between these versions depends on your needs and requirements. Both programs are designed for the diagnosis and repair of JCB equipment, but JCB ServiceMaster 4 has a more modern interface and expanded functionality than JCB Servicemaster 2. We were relevant for jcb servicemaster 2 download https://sites.google.com/view/jcb-servicemaster/home , because we still have even more old equipment and we have enough previous version. So build on your goals and objectives.