Looking inside Joomla Administration, you set “Force SSL to Entire Website”, because SSL is better.
If your host don’t support SSL, you can’t access your Joomla website.
Hei, stop, put down the gun … you don’t need to kill yourself 🙂
Open your Ftp Client and connect to Joomla file : search for configuration.php and set
public $force_ssl = '2';
public $force_ssl = '0';
Please, note :
normally configuration.php is protected by file permission, so you can’t modify it. You should before change file permission (on filezilla, right click, file permission) , enable write permission, modify force_ssl, transfer file and so restore original file permissions.