Trouble with the password on my live box.

Hi everyone i was wondering if you could help me as i'm a novice with computers.

  My family recently purchased a dell dimension 5150 with a wannadoo (now orange) livebox and dell provided a technician to install it. I have just bought a dell notebook 6400 and my wireless connection is unable to connect to the internet, as the broadband livebox has a security password on it. The problem is that i've tried inputting the WEP code as it asks, which found underneath the livebox but this is not unlocking the connection. It seems the technician has put on another password which no one knows the code for it. Ihave also tried unlocking the livebox on the dimension however it asks for the password to access this and again i do not know what the password is. Does any know how i can solve this problem, i have bought a router to allow me to go on the internet, however to secure this connection it asks for the same password as the livebox and as i do not know what it is i cannot secure my signal so i've unplugged the router and currently not using it. All your thoughts would be appreciated. 

                    Thanks very much