Usage: java [-options] class [args...] (to execute a class) or java [-options] -jar jarfile [args...] (to execute a jar file) where options include: -client to select the "client" VM -server to select the "server" VM -hotspot is a synonym for the "client" VM [deprecated] The default VM is client. -cp -classpath A ; separated list of directories, JAR archives, and ZIP archives to search for class files. -D= set a system property -verbose[:class|gc|jni] enable verbose output -version print product version and exit -version: require the specified version to run -showversion print product version and continue -jre-restrict-search | -jre-no-restrict-search include/exclude user private JREs in the version search -? -help print this help message -X print help on non-standard options -ea[:...|:] -enableassertions[:...|:] enable assertions -da[:...|:] -disableassertions[:...|:] disable assertions -esa | -enablesystemassertions enable system assertions -dsa | -disablesystemassertions disable system assertions -agentlib:[=] load native agent library , e.g. -agentlib:hprof see also, -agentlib:jdwp=help and -agentlib:hprof=help -agentpath:[=] load native agent library by full pathname -javaagent:[=] load Java programming language agent, see java.lang.instrument C:\l2server\l2j>-Dpython.home=c:/l2server/jython -Dpython.path=c:/l2server/l2j/d ata net.sf.l2j.Server '-Dpython.home' is not recognized as an internal or external command, operable program or batch file. Press any key to continue . . .