http server error Lotus Domino R5

Greetings,

I have Lotus Notes Domino Server R5 on Windows 2000 Server OS. When I want to start the HTTP web server on the Lotus Domino I get this message:
03/30/2004 12:18:57 PM HTTP Socket bind error, hostname/ip afgofile1.afgo.wvi.org
03/30/2004 12:18:57 PM HTTP server: Could not bind port 80. Port may be in use
03/30/2004 12:18:57 PM HTTP Web Server shutdown

Your help is appreciated.

Thank you