Definitively today I made some progress. Removed conflicting Java 1.6 and installed a fresh 1.7u4, and rebuilt on jbpm 5.3. Interesting is that I cannot found the "server" folder where to find the logs. Now I see after typing "ant start.demo", an error message like "JBOSS AS cannot start after 5 minutes". Looked ino the community and one advice was to set the env var JaVA_HOME to <install dir>\bin. So the conpilation was going fine and stil the AS cannot start.