Hello,
The Error is from IIS which is being used by the Symantec Endpoint Protection Manager.
Check these Articles below, which may assist you:
IIS is already installed and running but when installing the Symantec Endpoint Protection Manager (SEPM) console, you receive errors regarding IIS and W3SVC services
http://www.symantec.com/docs/TECH98146
IIS Error Displayed During Installation of the Symantec Endpoint Protection Manager
http://www.symantec.com/docs/TECH91538
"Internet Information service ISAPI Extensions (IIS ADMIN) and World Wide Web Publishing (W3SVC) need to be installed and running for this installation to continue." while installing Symantec Endpoint Protection Manager (SEPM).
http://www.symantec.com/docs/TECH105061
Hope these helps!!