| Both Apache and IIS use port 80 (the HTTP port) for communication, they both cannot open it so you need to tell one of them to use a different port.
For IIS open the MMC, -> RC Default Site -> select Properties -> Change the TCP Port to something else. and Apply & OK
Open a command prompt and type iisreset & press <enter>
For Apache open the httpd.conf file -> find Port and edit the number -> save the file and restart apache
Change one of the ports to a high number, 8080 or 8088 are common choices, then one server will run on localhost and the other will be localhost:port_no |