Plug Block Password Reset
This plugin is designed to make your Joomla site more secure by preventing attackers from resetting your administrator password.
Upload and install using the Joomla installer. Remember to enable the plugin in the plugin manager. Set the individuals that you wish to block password resetting for in the plugin parameters. You can block password resetting for selected individuals listed by id, or for specific groups.
You should only use this plugin if you are confident that you will not forget your admin password, or if you have access to your site database so that you can reset your password directly in an emergency.