|When you connect to your wifi you will need to enter the security key which usually is on a sticker underneath or on the side of your router. On this sticker you will see|
SSID: which is the name of the wifi that you are trying to connect to
WPA: this is your password
if you have changed your password and no longer remember it you will need to login to the router and change it. However i dont thin this is the issue in your case? try the above and let us know if it worked.