Download the Apache Tomcat server 6.0.x from the following webpage http://tomcat.apache.org/. On MS Windows you can use the self-explanatory MS installer to install Tomcat. For a Tomcat installation on other platforms, please use Google.

After the installation test if Tomcat in correctly installed by opening a browser to http://localhost:8080/. This should open the Tomcat main page and if you see this page then Tomcat is correctly installed.

After verifying that Tomcat is correctly installed, stop Tomcat. Eclipse WTP is try to start Tomcat itself. If Tomcat is already running Eclipse WTP will not be able to use it for development.