Disable JRE in Windows Java control panel??
You can edit the C:/Users/Admin/AppData/LocalLow/Sun/Java/Deployment/deployment.properties file.
Search for something like this inside the deployment.properties file.
Change the value for deployment.javaws.jre.2.enabled to false for the JRE versions which you want to turn off.
NOTE: Numberings will differ in your case. I just gave an example.
Also place the deployment.properties file in C:\Windows\Sun\Deployment so that it will reflect for all the users.