SOLVED : Since campsite 3.5, I use this software and I am very pleased with your efforts and the quality of the platform, BUT I had awlays search to find and correct stupid bugs.
So, I could not continue the installation (clean and new, and just downloaded for sourceforge) because of that bug :
In the CampTemplate.php under the /install/classes/CampTemplate.php
I got it :) ! The problem was "as expected" the Windows-Path-Dilemma. I can understand @Andrey+Podshivalov saying "windows is not recommanded" :) !
To get PEAR working under XAMPP, just look into php.ini for:include_path , and check whether the assigned path has a drive letter, if so remove it. It must look like this: