This could be an issue of the permission of the Joomla installation directories.
For manual installation
The cache component is installed within /administrator/components/com_jreache.
Also notice the table that should be created for the cache repository:
CREATE TABLE `jos_jrecache_repository` (
`id` int(11) NOT NULL auto_increment,
`url` varchar(255) default NULL,
`cache_file` varchar(255) default NULL,
`cache_size` varchar(10) default NULL,
`datetime` datetime default NULL,
`is_may_cached` tinyint(4) default NULL,
`checked_out` int(11) default NULL,
`cookie_info` varchar(255) default NULL,
PRIMARY KEY (`id`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8
Also insert a row into the components table:
INSERT INTO `jos_components` ( `name`, `link`, `menuid`, `parent`, `admin_menu_link`, `admin_menu_alt`, `option`, `ordering`, `admin_menu_img`, `iscore`, `params`, `enabled`) VALUES ( 'JRE - Cache extended', 'option=com_jrecache', 0, 0, 'option=com_jrecache', 'JRE - Cache extended', 'com_jrecache', 0, 'js/ThemeOffice/component.png', 0, '', 1)
After this you need to replace the /index.php file with the com_jrecache/install_files/index.pat and the /administrator/index.php with com_jrecache/install_files/index_admin.pat (in case of J1.0)
Then goto the administrator part and enable the cache.
Regards,
Richard