Hello Changed Wifi Identity,
The router will change back to default settings if the reset button was pressed (this is a small usually red button located on either the back or the bottom of the router) or the router was reset to factory default through the router settings. If you purchased the router from Cox and you have the Linksys® EasyLink Advisor Setup Wizard CD, you can find instructions here on how to secure your router. If the router was not purchased from Cox or you no longer have the CD, you can contact Linksys for support at 1-800-326-7114 http://homesupport.cisco.com/en-us/wireless/linksys , contact our Cox Tech Solutions at 877-832-7658 (fee based support), or one of our forum members maybe be able to give you mare information on entering your router settings to secure your router (they would need to know the model of the Linksys router you are using).