That is a generic error message. First, uncheck "Show Friendly HTTP Errors" in your copy of Internet Explorer (Tools -> Options -> Advanced).
Then reload the page
Then scroll down a bit further till you see the real error message. Eg, if the server can not be located, you will see "Can not locate server or DNS error".
If the page can't be found, you'll see:
"404 Not Found"
If an error occured, you will see:
"500 Internal Server Error..." (plus error message and details). Post that to this group.
Microsoft MVP - Windows Server (IIS)