96519 joomla expert

One of my sites that uses joomla is showing an error on the index page and on inner content pages, seems to be looking for something, but nothing is there ? see below for error message Not Found The requested URL / was not found on this server. -------------------------------------------------------------------------------- Apache Server at [login to view URL] Port 80 the site is see above....... the site works fine with no glitches, so this is very strange