I know this is quite a delayed reply, but this may help others having the same issue.
I had this same type of error pop up when I was configuring an application to listen on port 443. As a result my Apache had to be configured to listen on port 443.
It could not bind to socket 443 due to it already being bound to by another application. I found that Skype and LogMeIn both bind on 443 and will block Apache from starting and listening on 443.
Shutting down these services and starting Apache made it work. If I were you I would use the
netstat command and look at what is bound to port 80. If you have an application taking up a port 80 bind that you do not need, shut down the service for that application.
netstat -b did the trick (to view binds). Make sure you run the command prompt as Administrator.
Another Note: I am surprised it will not bind to 80. Being the common port for http, I thought this port could be bound to by many applications. Regardless, it is worth a try if you are still experiencing the error.