Hello, So I create, long time ago, Main Menu in HTML, which is my Overture Page; when opening Firefox, this page appears well, but, it's the only one: when clicking an item in this Menu, calling thus a Sub-Menu, this Sub Menu refuses to open, saying it don't find the HTML file, which is well there, and with its htm extension, and in the same directory as the Overture page; and it's the same with all other sub-menus and sub sub menus, so, no question of a typing fault, all is correct! But, when clicking, via the Explorer (Windows 7 Family Premium Edition) on ANY htm file of the Menu, it opens perfectly in Firefox 28! The cause seems so to be in Firefox... I have exactly the same System Menu on an other PC, running under Windows XP SP3: no problem at all, and also with Firefox 28... Thanks for your help!