Problem with Apache server in windows

I have install the xampp. in which i have also select the Apache server to install by default. after the successful installation. My SQL server is working properly.
But when i try to start Apache server it give me a message that port 80 is busy. I open all the services and in which i stop the Microsoft IIS which is using the port 80 and then try to start Apache server but it still gives the message that the port 80 is busy. what should i do to start my Apache server the version of my xampp is 1.7.4
