Netgear DGB111G Router

Question

Complete all of the installation cd fine no problem until you get to the bit where it asks for your username and password. Not the part where you have to input username: admin and password: password, but the next one where it says put in what you would normally put in to sign on to the internet. Well 1) we don't need to sign in because broadband automatically connects when we turn on the computer and 2) When we put in the username and password that were originally entered when we joined talk talk broadband, it says incorrect username and password! But we tried ringing talk talk and they said for any technical support like that we have to pay an extra £35 which we'll probably end up doing but jus thought it may be something silly we're missing and thought i'd see if you guys could help?
Cathy