Many older linksys routers have default username left blank, and the password is: admin .
This tip may come in useful in case of an emergency, like the internet stops working, or not being able to establish a connection with a wireless router. One then logs onto their router (gateway address), which is typically 192.168.1.1. (or 192.168.15.1).
Connecting wirelessly this way can be a bit finniky, so your best bet is to plug into the router (this is with an internet cable from your computer to your router).
You should then have full access to the details of your router.