Lost my wireless connection

[TThibodaux]

Hello,
I got a new laptop lenovo T420 and it asked for the p number under the router. I gave the number and it changed my unsecured router to a secured one. Not how do I get the password and the security key.

 

[Emerald]

http://www.tomshardware.com/forum/31382-43-find-security-password-wireless-router