try the tutorial on the other laptop.
Is the router updated? Can you log on to the router? This tutorial will show you how to log on, How to Get to Your Router's Configuration Settings | eHow.com
- the password should be different to log on to the router than the password you use to connect wirelessly. Hopefully you know the router password. If you have never created a password for it, create one now. You'll have to leave the password space blank to log in.
I could probably help you out more with this once I get home, but you're basically looking for the ip addresses of all the computers in the house. Make sure that the addresses are different for each laptop/device. For now, the most important thing is making sure the router is updated (look for a button that says so).