The Java Interpreter path is set default in the Java file of your computer (by default Program Files\Java\jre6\bin\java.exe).
To customize your Java Interpreter path:
If needed, click the Talend node in the tree view of the [Preferences] dialog box.
Enter a path in the Java interpreter field if the default directory does not display the right path.
On the same view, you can also change the preview limit and the path to the temporary files or the OS language.