(98)Address already in use: make_sock: could not bind to address 0.0.0.0:443

I was setting up SSL on localhost to get https://localhost. I was successfully able to get the digital signature, sign it. But when i restarted apache2 I was getting this error:

(98)Address already in use: make_sock: could not bind to address 0.0.0.0:443

This means that port was already being listened. Hence at first I tried to kill the processes which are using that port. When this didn't work I tried this:

open /etc/apache2/ports.conf

Remove the line outside any <IfModule> tag which says Listen 443

Problem solved!!