make_sock could not bind to address 0.0.0.0:80 no listening sockets available

I kept wondering for a moment what could be running on port 80 coz the machine was newly setup and it didn’t have IIS or any other web server. It quickly struck my mind that once a friend of mine told me about Skype causing a conflict when he installed Apache. On this machine Skype was running already and I was logged in on Skype as well. So first thing I did was to exit Skype and started Apache. Now the Apache service started without any issues. With a little bit of research I found out that Skype was the culprit in this case because Skype uses port 80 as an alternative port for communication. Now since Apache Web Server is running, I started Skype and logged in and it was working smoothly as well. So starting Skype after Apache is started will solve the issue in one way as Skype will use a different port. But the better solution is to disable the Skype option of using port 80 as an alternative. On Skype you can do this by

 - Goto Tools -> Options -> Connection
 - [Untick] Use port 80 and 443 as alternatives for incoming connections
 - Click Save and restart Skype to apply the changes.

Without changing this behavior in Skype, we can do the other way around as well. In httpd.conf file for Apache we can set the “listen” port to 8080 (as an alternative port) which will solve the issue but I preferred to use port 80 itself for Apache. But its just me. You have two solutions in hand and the choice is yours