At the moment I see IIS (Windows Web Server) is running on your computer and unless this is disabled in your Windows Control Panel or you change the ports in Apache then XAMPP will not be able to start Apache or MySQL as they need to have those ports 80 - 443 and 3306 exclusively to be able to run.
(right click and select to run as administrator) and all ports should be free
to be able to run XAMPP without issue.
Or you could just use IIS for your web site as it looks like it is already running minus a web site to serve.
If you want to use XAMPP then you need to revert your httpd.conf file back to the default and then use the .\xampp\apache\conf\extra\httpd-vhosts.conf
Unfortunately the forum Search facility appears to be broken
at this time or a search for vhost
would give you some very useful and helpful posts.
This Google search in French
may give you some clues.
Same Google search in English
See these threads for some possible help:http://community.apachefriends.org/f/viewtopic.php?f=16&t=32030http://community.apachefriends.org/f/viewtopic.php?f=16&t=31892
Or this thread regarding a home network virtual host:http://community.apachefriends.org/f/viewtopic.php?f=16&t=32264
And for authoritative help in your language go to:http://httpd.apache.org/docs/2.2/fr/vhosts/http://httpd.apache.org/docs/2.2/fr/vhosts/examples.html
And the full documentation here:http://httpd.apache.org/docs/2.2/fr/
Good luck - bonne chance