Prevent java 6 from auto updating
After April 2013 further security updates to JRE 6 will only be available through My Oracle Support and will require a support contract with Oracle. By default, Java applications that are accessed through a web-browser or webstart will use the latest version of Java on the system.It is possible for an application to specifiy the Java version required.Java update can only be disabled with administrative rights, so you need to run the Java control panel elevated.Since you can't do this through the control panel, you need to run the applet through its executable.If an application has left it up to the system on which it is running to determine which version to use, and you have JRE 6 and JRE 7, only JRE 7 will be used.
As suspected this problem was due to the Java control panel requiring Admin Privileges to disable the automatic update.
Note that the registry changes above alone are not enough to prevent the Java updater from running.
To prevent it from starting, and subsequently preventing the famous UAC prompt from appearing, follow the next step.
Unless you have a support contract with Oracle you will not be able to get security updates for JRE 6 from Oracle after February 2013 and it is not advisable to keep older versions of Java on your system.
Nevertheless if you would like to continue to have both versions, JRE 6 and JRE 7 can be installed on the same computer.