.java files will not open?

you can open .java files in a simple text editor like Notepad or Wordpad... at the beginners level, that's all you need... to compile and run java programs, you need the Java Development Kit (JDK)... first install it and set up your environment variables.. instructions on doing that can be found here.. http://www.jibble.org/settingupjava.php

to compile a java program, go to the command prompt and navigate to the folder where you saved your .java file and type in this>> javac YourFileName.java

then to run your java program type in this>> java YourClassName

Java files are just raw code, or your source code if you want to get all technical. To run a Java applet, you first need to compile the source code in .java files either from the command line or with an IDE (Integrative Developing Environment) like Eclipse or Netbeans. If you have never used an IDE before, use Netbeans because the UI is user friendly and far less confusing compared to Eclipse. Since I take it you havent yet written a program, to open .java files to edit previous code, use Notepad++ or an IDE.

Make your life easier. Install the NetBeans IDE.