Error starting Apache (httpd start fails)

[cfspence]

Advance apologies for the utter novice question.

In attempting to fix a slow server problem, I have somehow managed to "break" Apache. It will not now start (even when the system reboots).

Here is the error message:

# /etc/init.d/httpd start
Starting httpd: (98)Address already in use: make_sock: could not bind to address [::]:80
(98)Address already in use: make_sock: could not bind to address 0.0.0.0:80
no listening sockets available, shutting down
Unable to open logs
[FAILED]

It appears that port 80 is busy and not available for listening. How do I correct this?

Thanks in advance for your help.
--Clay