This case can be seen when the user formats the PC and installs a new OS wherein you need to configure and setup wireless connection again. Since the password is always fed in you never remember it and when your PC is formatted, its all gone. You could get back your WI FI passwords using some recovery softwares available in the web. You could also reset your WEP or WPA key in the router and then log into the router and change your Wi Fi security key.
