To run programs written in the Java programming language we need Java virtual machine, runtime class libraries, and Java application launcher. The Java SE Runtime Environment contains all the above. This application is freely available from Sun. After you entering the download page first you have to accept their agreement policies. Then only you can download Java Runtime Environment (JRE) 6 for the required platform.
Download Java Runtime Environment (JRE) 6
Download Java Runtime Environment (JRE) 6