When you compile, you are turning the source code into a bytecode class file.
You would have started with a file with a .java extension, this is your source code.
After you have compiled a source code file, you will be left with two files: a compiled class file (.class) and the original source code (.java) that you used to create the class.
It would be much easier for you to modify the source code and then recompile the source code, than to modify the executable.
If you wanted to modify the executable, the compiled class file would need to be decompiled if you needed to edit it. There are tools available do this. Try Goolgeling "Java Decompilers". But I would strongly recommend that you go with modifying the original source.
Joined: Jun 18, 2010
ok thank you
Joined: Jun 01, 2010
EDIT: This was a response to your response that you edited, so really doesn't make sense anymore
Do you mean the error is displayed when you double click on the java file? If so, this is a problem with the configuration on your Wndows box. You haven't associated files with the .java extension with an application that will load it. Pick Notepad (or your favorite text editor) and you'll be able to open the file.