Options +FollowSymlinks
RewriteEngine on

RewriteCond %{HTTP_HOST} ^http://installation-reseau.com$
RewriteRule ^(.*) http://www.installation-reseau.com//$1 [QSA,L,R=301]

RewriteRule ^portfolio-isphers.html$ /index.php?pn=accueil [L]
RewriteRule ^contact.html$ /index.php?pn=contact
RewriteRule ^error404.html$ /index.php?pn=error404