java -cp . HelloWorldYou cannot run the class if it was compiled for a newer version of java. You can check what version of java you are running it with by using the command
java -versionYou can change the version of java you are using by either specifying the complete path to the java executable on the command line, or changing your shell's path so that the desired java version comes at the start.
javac -cp . HelloWorld.javaAgain, you can use -version to check the version you are using.
%SystemRoot%\system32;%SystemRoot%;%SystemRoot%\System32\Wbem;"C:\Program Files\Symantec\Norton Ghost 2003\";C:\Program Files\Java\jdk1.6.0\bin\There is an "Edit" button so you can change it. The location shown above is the default (I think) but do check that it is correct for your system: ie, go into WindowsExplorer or "My Computer" and actually locate the bin folder of the java distribution. Unless you use it, you can clobber the java 1.3 entry in your path variable.
I removed the oracle 1.3 jdk from path and now it displays the correct versionWhat about running the classes you compiled with the IDE?
I get a Java Virtual Machine error: Could not find the main class. Program will exit.