New Laptop Connection

I have a new laptop that I'm trying to connect to my Wireless-G Broadband Router so I can have wireless internet connection. I have been following the instructions on the disk, but at a certain point, it asks for a password. I don't know what it wants, as I don't remember a password when I hooked this router up to my wife's laptop several months ago. I have a similar problem, but I have a new lap top and recently install a Linksys router. After completing the install and going wireless. After a few tries going wireless the program will disappear and have to reinstall wireless program. How can I prevent to stop this from happening again?Note: I am a new at this and would appreciate your help.