Its not a XAMPP issue is what I am telling you.Look at the links that are being generated
From the home/mainmenu of the site, i want to call some other sitepages, but every time the xampp-mainpage appears instead of one of the site-pages.
that is because, almost assuredly, the Joomla links are calling "/index.php?action=" or something of that nature. AND, by default, in XAMPP the 'index.php' in the root of XAMPP redirects the user to /xampp/index.php (which is the XAMPP Welcome Page.)
The fix is a matter of either 'placing' Joomla in the root of htdocs or finding the URL redirect, either in Joomla or on your site if Joomla was not set up in the root on your live server. Most CMS's or Blog scripts use their primary URL (http://www.youflippingdomain.net/index.php
- for instance) to create script actions. The index page of the script is effectively a command processor. You can see how it works by watching the URL's as Joomla does things. HOW it is fixed is specific to the CMS or Blogging software.
The right answer here is a matter of two things - Understanding what your setup is/was and learning how Joomla creates its URLs.
Try a Google on 'Joomla URL' or read visit Joomla's site or Forumshttp://docs.joomla.org/Main_Pagehttp://forum.joomla.org/