Joomla! 1.5 and 1.7 one click install scripts have now been removed from the eXtend hosting control panel. This does not effect existing site’s using Joomla! 1.5 or 1.7 however when creating a new installation of Joomla! only versions 2.5 and 3.0 are now available.
If you have any questions please contact our support team here.