Tersus applications require servlet support which is not provided by IIS.
We recommend using Tomcat, which includes a standalone http server (so IIS is not really needed).
If you have other reasons to keep IIS, you can configure Tomcat as the servlet engine as described in http://tomcat.apache.org/connectors-doc/webserver_howto/iis.html.
Another option would be to setup IIS and Tomcat side-by-side (by default they use different ports) and setup redirection from IIS to Tomcat.
For best results, use the Firefox browser..