OS-Windows Server 2008 Standard R2

IIS is running port 80 works service desk is supposed to be on 8080 everything was working on it till yesterday than it quit responding I have looked at the services they all appear to be running but have restarted the server several times with nothing changing tried connecting with localhost on port 80 on the server and nothing any help would be appreciated what services do I need to look closer at to make sure everything is up and running we have been using this product for 6 years almost this is the first major hiccup.