Error code 51330 occurs when a Nintendo Wii fails to connect to the Internet due to an incorrect password input for the wireless router. This code usually occurs due to human or player error when the wireless router password is entered incorrectly into the game console's interface.
The password to a wireless router is also known as a WEP or WPA key and can be pre-set by the user. Wireless router passwords are case sensitive, and a single mistake results in a 51330 error. Most wireless routers are manufactured with a default password printed on a sticker on the bottom.