cgi-bin can't access

[anyunde]

cgi-bin can't access
I uploaded the html files in cgi-bin folde today and when I try to access it,
i get "500 Internal Server Error". The page I'm using it on is "http://anyunderground.hostrocket.com/cgi-bin/index.htm".

Part of the error message is also:
"The server encountered an internal error or misconfiguration and was
unable to complete your request."

Moreover, the same result is obtained even if it installs a cgi script.

What's wrong?