You need Tomcat installed and working to then install the connection agent.
what is the problem though ? if it is ‘unable to start service’ then consider that it may be a permission issue or some security setting in Windows Server 2008 stopping you. The Server event log should give you more detail to the problem but also look at how you can ‘google’ such things. I can see searching for ‘Windows 2008 Server Tomcat’ brings up a number of entries. They all seem to be referring to the default ‘settings’ in Windows 2008 which based on your earlier post would seem to be your problem