This should address any configuration problems and update the Java Runtime Environment to the latest version. First, uninstall Java as you would remove any other software on your PC.

RegEdit Using Java. When designing Java desktop applications for consumer use, you may need to access users' Registries to read information about particular hardware configurations. In order to do ...

A Java Archive, or JAR file, contains all of the various components that make up a self-contained, executable Java application, deployable Java applet or, most commonly, a Java library to which any ...