To answer your question, as this port is not used by Skype, rather by some other internal applications, I followed the below steps to resolve the issue:
Step 1 - From the XAMPP Control Panel, under Apache, click the Config button, and select the Apache (httpd.conf).
Inside the httpd.conf file, somehow I found a line that says:
Following which, I changed the 80 into any number / port you want. In my scenario I’m using port 8080.
Still from the httpd.conf file, I found another line that says:
Change 80 to 8080.
Step 2 - From the XAMPP Control Panel, under Apache, click the Config button again, but this time select the Apache (httpd-ssl.conf). Inside the httpd-ssl.conf file, find line that says
And change the 443 into any number / port you want. I’ll use 4433 as the new port number.
Still from the httpd-ssl.conf file, find another line that says
<VirtualHost _default_:443> ServerName localhost:443
And change 443 to 4433.
<VirtualHost _default_:4433> ServerName localhost:4433
Always never foresee, saving the httpd.conf and httpd-ssl.conf files after performing some changes. Then restart the Apache service.