Thanks for your quick reply.
I understand you cannot check my website on local host.
Before posting, I'v made sure, of course, that everything was OK ( technical requirements & joomla installation), I have the latest version of Xamp, with latest version of php and Mysql.
In fact, I've been working with many different templates before this one on this version, and everything worked perfectly, even all the extensions i've downloaded. Except that, I agree, some may have sometimes conflicts between each other.
I decided to buy this one, to avoid this kind of conflict, and get an "all in one" template, with gallery, slideshow, etc...
Unfortunately, even though i've downloaded the JD catalog2 for joomla 2.5, there is no doubt about that, here is the name of the file I downloaded pkg_dj-catalog2_AIO_2.2.10.zip, it is not working at all on this local site.
As for the Quickstart.zip file, the exact message was "the archive is damaged or its format is unknown", i just try to install it again on another new data base, this error message came again from Winrar program when trying to extract it.
I have another website on a live server, and I've installed the dj catalog2 extension with no problem this time although I did exactly the same ... Unfortunately, for the moment I need this template for the site which is not on a live server yet (I do not have access to all files on the live server, so i cannot create different data bases for testing), so that's not helping me...
I guess, apparently, there is something wrong with xamp and this extension. I'll have to change localhost server and try again...
Thanks anyway for answering.