Apache Address already in use: make_sock: could not bind to port 80 error and solution

while configuration for apache , if we get an error like this :-

Apache Address already in use: make_sock: could not bind to port 80 error and solution

Then chk following service is running ( using port 80 or not)

tux enabled (a kernel level web server) or something similar , stop that ..

Also you can find all the open files on the port 80 using command

lsof -i:80

then you can kill all those PID then you can restart apache.