Question: I have a question related to PHP. I am .net developer. I usually work on asp.net and c#.I installed Visual Studio and SQL Server in my laptop.Now I am trying to Install Xampp server on my system. Here I getting some problem.After Installation When it check for port. It show me message port 80 or 443 aleardy in use apache server installation is failed. I Guess it is happening due to IIS installed in my system. I stopped the IIS and Installed it again But the same problem is coming again. I uninstall the Skype too for this but nothing is working for me. Please tell me why this is happening and what is the solution for this. I hope you understand what is my problem. Please help me for this

Answer: 
Fix for this Problem:

Open up `Skype` and go to `Tools` and `select` Options. From the list that appears select `Advanced` and then `Connection`. There will probably be a check mark inside where it says `“Use port 80 and 443 as alternatives for incoming connections”` just unchecked that box and save your changes. `Skype` will still function normally and now `XAMPP` will be able to use port 80 to run.

[Useful link](http://windowsvj.com/wpblog/xampp-installation-error-port-80-or-443-already-in-use-apache2-2-service-failed/)

if you have no `Skype` installed

* Locate the file `httpd.conf`. This file should be found in
`C:\xampp\apache\conf` (or whichever directory you installed `XAMPP`.
* Open the file using a `text editor`.
* Locate the line that says `Listen 80`.
* Change the port number `(80)` to a different number(eg. 1234).
* Restart the `Apache Server` to have the change take effect. Do this  

by clicking on the `Stop` button on the `XAMPP` control panel and  

then clicking on the `Start` button.
* When you connect to the `Apache` Server, you will have to `append`  

the port number to the `URL`, previously where you typed `localhost`,
you will now have to type `localhost:1234`

[Another Useful link](http://complete-concrete-concise.com/web-tools/how-to-change-the-apache-port-in-xampp)
As it says - the port 80 and 443 are already in use. It means that the ports 80 and 443 are already in use by some other server or application. When i faced this issue, it was wamp server that was using these ports(not skype in my case).

What i did to resolve this is that I changed the ports for xampp.

How: 

1. I configured the httpd.conf & httpd-ssl.conf files for Apache.
2. I changed values for Listen 80(where 80 is the port number) to another random port number(I chose 88) in httpd.conf file.
3. I changed values for Listen 443(where 443 is the port number) to another random port number(I chose 4433) in httpd-ssl.conf file.

Make sure you Apache server doesnt use the ports 80 and 443 anywhere in the configuration files, then it will work fluently.