The technology owner of Java applets claim that they disable running Java applets without a certificate for security issues, but I think it's nonsense. Many reputable websites use Java applets to demonstrate a concept, a mathematical model, an image processing algorithm, and so on. If they make web browsers unable to run the Java applet how are those websites supposed to demonstrate their ideas?
For example I came across http://www.oneminuteinfo.com/2010/03/how-to-solve-rubiks-cube.html because I wanted to learn how to solve the Rubik's cube. Without seeing it inside a Java applet how do I know how to solve a Rubik's cube?
Anyway I'll walk you through exactly how to enable your web browsers to run an embedded Java applet in any website.
This tutorial is for Windows 7.
Configure Java settings.
In Start menu type Java and select Java under Control Panel. This is Java Control Panel that allows you to configure Java related settings.
Go to Update tab and uncheck "Check update automatically" checkbox. I hate my PC doing updates without my permission.
Go to Advanced tab and here is where you make browsers able to run applets. There are so many settings here that I forgot the changes I've made, but just go through them and check/uncheck the ones that are related to security. For example, I uncheck "Activate the next generation Java Plug-in" and select "Never check for updates" for "JRE automatic update". Under Security -> Certificate I select "Never use certificate". I think this is the setting that makes the difference.
Click OK and restart your web browser. Use either Internet Explorer or Firefox. Don't use Chrome.
If you want to test go to http://www.oneminuteinfo.com/2010/03/how-to-solve-rubiks-cube.html and see if you see and can play with the Rubik's cube inside the Java applet.
Of course, if you go to a malicious website with a malicious Java applet your system may be compromised. If you are not willing to take the risk then ignore this tutorial.
Questions? Let me know!