Thread: i keep getting this error

plz, i'm new to this Java. i've installed jDK 1.6 and configured the Environment Variable yet each time i compile and try to run a Hello World program in DOS, i get this message;
D:\javafiles>javac Helloworld.java
Helloworld.java:3: class HelloWorld is public, should be declared in a file name
d HelloWorld.java
public class HelloWorld {
^
1 error
here is the actual program;

// A program to display the message
// "Hello World!" on standard output
public class HelloWorld {
public static void main(String[] args) {
System.out.println("Hello World!");
}
} // end of class HelloWorld

Plz any help rendered will be highly appreciated.

java is case sensitive. Check your cases in the class name and the file name - they should be identical.

i changed the root drive from d: to C:
then tried to compile and run this: (it ran perfectly in Eclipse platform, but i would love to learn Java with JDK)

public class Hello {
 
	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
System.out.println ("Hello World!");
	}
 
}

it compiled and created a Helloworld.class file in the folder, but gives me this error message when i try to run using the 'java Helloworld.java' command
C:\javafiles>java helloworld.java
Exception in thread "main" java.lang.NoClassDefFoundError: helloworld/java
Caused by: java.lang.ClassNotFoundException: helloworld.java
at java.net.URLClassLoader$1.run(URLClassLoader.java: 202)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.j ava:190)
at java.lang.ClassLoader.loadClass(ClassLoader.java:3 06)
at sun.misc.Launcher$AppClassLoader.loadClass(Launche r.java:301)
at java.lang.ClassLoader.loadClass(ClassLoader.java:2 47)
Could not find the main class: helloworld.java. Program will exit.

For a class named Helloworld.class, try "java Helloworld"