title: yum command not working using Red Hat
body: <p>I want to install java using yum command (Red Hat Enterprise Linux Version 5) but exception arises..</p>
  
  <pre><code>$ yum install java-1.6.0-openjdk
  Loading "rhnplugin" plugin
  Loading "security" plugin
  Loading "installonlyn" plugin
  **This system is not registered with RHN.**
  RHN support will be disabled.
  </code></pre>
  
  <p>plz help i m new for linux..</p>