Apache Friends Support Forum

When I installed XAMPP, once it began the service of apache. It has the problem error saying the Port 80 is blocked, what's the problem and how can i fix it?

http://www.apachefriends.org/en/faq-xam ... ml#nostart

there is more helpfull FAQ
http://www.apachefriends.org/en/faq-xampp-windows.html

If i really need to run 2 server: IIS and Apache at the same time, how can i config the file and change the port to let 2 server run independently?