wSecure hides admin URL so that default URL will no longer bring up the admin page. Only people who enter the secret key will be able to access admin
In order for wSecure to work the wSecure plugin must be activated. Go to Plugins Manager and look for the "wSecure Authentication". Make sure this plug in is activated.
Click on the "Help" link present on wSecure Authentication plugin page. Here you will find help on how to use this plugin.