Hi!
If you want to use external libraries or sources, you don't have to have them in your jdk directory. If you're using a development environment (e.g. Eclipse, JBuilder, ...) you can include them there, otherwise you have to add them to the java classpath when using javac.
The easiest way to do that would be if there's a .jar file in that archive you downloaded. In that case, just add the option
- -cp C:\path\to\jar\file.jar;.
to the arguments. (Assuming, you're in the directory of your program - otherwise replace the "." with the path to that.)
Greetings,
Nepomuk