XAMPP is a free and open source cross-platform web server package, consisting mainly of the Apache HTTP Server, MySQL database, and interpreters for scripts written in the PHP and Perl programming languages.
Skype is a software application that allows users to make voice calls over the Internet. Calls to other users within the Skype service are free, while calls to both traditional landline telephones and mobile phones can be made for a nominal fee using a debit-based user account system.
Skype use port 80 as alternatives for incoming connections and XAMPP use the port 80 as well. By default the Skype port option is checked and if you start XAMPP it will not start, shows busy.
So to get rid of this problem simply open the Skype->Tools->Options->Advanced, on connection, just Un-Check before “Use port 80 and 443 as alternatives for incoming connections” and Save it.
Now quit and reopen the Skype and start using XAMPP and Skype together.