We need the terminal window to access the Java compiler called “javac”. This is the program that will read the code in the FirstApplet.java file, and translate it into a language that your computer can understand. This process is called compiling. Just like Java applications, Java applets must be compiled too.
To run javac from the terminal window, you need to tell your computer where it is. On my machine, it’s in a directory called “C:\Program Files\Java\jdk1.6.0_06\bin”. If you don’t have this directory, then do a file search in Windows Explorer for “javac” and find out where it lives.
Once you’ve found its location, type the following command into the terminal window:
set path= *the directory where javac lives*
set path=C:\Program Files\Java\jdk1.6.0_06\bin
Press Enter. The terminal window won’t do anything flashy, it will just return to the command prompt. However, the path to the compiler has now been set.