Network Key? wifi password not it

I have a new (to me) Dell computer. It is asking for the Network Key for my wifi.  I have entered my wifi password and that is not it.  I am not sure what Netwrok autentication I should select (open, 

If I do Open, WEP and enter my wifi password it says: The network password neds to be 40bits or 104bits depdning on your network configurations. This can be entered as 5 or 13 ascii characters or 10 or 26 hexadecimal characters.

??

Should I choose a differfent Network Authentication and Data Encription combination? What is my network key if not my wifi password?