How do I free my port 80 on localhost Windows?

I installed XAMPP 1.6.8 and for some reason it didn't work. Later realized port 80 is not free or not listening. How can I release it or make it free?

Thanks a lot!

That agony has been solved for me. I found out that what was taking over port 80 is http api service. I wrote in cmd:

net stop http

Asked me "The following services will be stopped, do you want to continue?" Pressed y

It stopped a number of services actually.

Then wrote localhost and wallah, Apache is up and running on port 80.
Hope this helps

Important: Skype uses port 80 by default, you can change this in skype options > advanced > connection - and uncheck "use port 80"

netstat -ano

That will show you the PID of the process that is listening on port 80. After that, open the Task Manager -> Processes tab. From the View -> Select Columns menu, enable the PID column, and you will see the name of the process listening on port 80.

netstat -a -b

Should tell you what program is bound to port 80