In this case, we might need to use different port for Apache web server.
Recommend to port 88, 8088, 8888 and so on ( 8 looks and feel goods for me )
What changes need to be done?
1. Get your httpd.conf, usually located inside apache installation and inner conf folder.
Example of my httpd.conf location and I am planning to use 8088 as my custom port:
C:\xampplite\apache\conf\httpd.conf
2. Change the default Listen 80 to your custom port
#
# Listen: Allows you to bind Apache to specific IP addresses and/or
# ports, instead of the default. See also the
# directive.
#
# Change this to Listen on specific IP addresses as shown below to
# prevent Apache from glomming onto all bound IP addresses (0.0.0.0)
#
#Listen 12.34.56.78:80
Listen 8088
3. Change Server Name with the correct port too.
#
# ServerName gives the name and port that the server uses to identify itself.
# This can often be determined automatically, but we recommend you specify
# it explicitly to prevent problems during startup.
#
# If your host doesn't have a registered DNS name, enter its IP address here.
#
ServerName localhost:8088
4. Restart Apache server and you can browser with http://localhost:8088/
Incase you have problem to check your port, you can always run this application bundle with XAMPP named: xampp-portcheck.exe
It will shown you which port are occupied by which programs.
You can try to stop your IIS and start Apache before IIS.
Hope this help.