Open the html file with your browser to view it.
Actually, I just updated all my EJS simulations to latest version.
You will find jar file if you download it again. You can double click the file to run it if you have JRE installed!
However, if you have WINZIP/WINRAR installed. It will change the default program to open the jar file from java program into WINRAR.
You can change the default program if you know how to change the default (in control panel).
The easiest way is to download and re-install [url=http://www.java.com/en/download/manual.jsp]Java Run time[/url] again.