Javac not recognized as a command

Question

When I go to the directory where I saved my code and type "javac HelloWorld.java" into the windows command prompt, it says that such a command does not exist. I have JDK 6 update 13. I found javac.exe in C:\Program Files\Java\jdk1.6.0_13\bin. When I type javac there it shows something like a list of commands. Does anyone know how to fix this?

Answer 1

I finally found a good video that explained it. Now it compiled properly.
But for some reason the program itself does not work:
class HelloWorld {
  public static void main (String args[]) {
    System.out.println("Hello World!");
}when I run it it says:
c:\Documents\Software Projects\Java\Hello World>javac HelloWorld.java
c:\Documents\Software Projects\Java\Hello World>java HelloWorld.class
Exception in thread "main" java.lang.NoClassDefFoundError: HelloWorld/class
Caused by: java.lang.ClassNotFoundException: HelloWorld.class
        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)
        at java.lang.ClassLoader.loadClassInternal(Unknown Source)
Could not find the main class: HelloWorld.class.  Program will exit.
c:\Documents\Software Projects\Java\Hello World>Is there an error in the program (I found it in some online java tutorial)?