good, in this way I can launch it even without set env varibles C:\ecj>java ec.Evolve -file ec\app\tutorial1\tutorial1.params I set Path and CLASSPATH either "c:\ecj\" (without "). And it doens't make any difference. In fact if I type: C:\>java ec.Evolve -file tutorial1.params Exception in thread "main" java.lang.NoClassDefFoundError: ec/Evolve Caused by: java.lang.ClassNotFoundException: ec.Evolve at java.net.URLClassLoader$1.run(Unknown Source) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) Could not find the main class: ec.Evolve. Program will exit. The error is the same; or I missed something about the meaning of "path", or something went wrong (I even did reboot). Any hints? thanks.