Before answering your question, just wann ans this simple question : Why we need PATH and CLASSPATH?

Answer:

1) PATH: You need to set PATH to compile Java source code, create JAVA CLASS FILES and Operating System to load classes at runtime.

2) CLASSPATH: This is used by JVM and not by OS.

Answer to your question :

Just make sure you have Modified PATH variable (Windows System Environmental Variable) so that it points to bin dir which contains all exe for example: java,javac and etc. In my case it is like this : ;C:\Program Files\Java\jre7\bin.

So, it doesn't matter your system is 32 bit/64 bit until and unless you specify/Modify the PATH variable correctly.

No need to print the default classpath. In Java, the default classpath is just the current directory:

If -classpath and -cp are not used and CLASSPATH is not set, the user class path consists of the current directory (.).

(documentation of java:)

Note: For completeness' sake: Theree are two other paths where java will look for stuff:

• the bootstrap class path
• the extension directory

The bootstrap class path by default points to parts of the JDK, and you almost never want to mess with it (unless you want to override part of the JDK), so you probably should not worry about it. The extension directories are for extending the JDK; see http://docs.oracle.com/javase/7/docs/technotes/guides/extensions/index.html