2 macbooks can't log on to home wifi

this is frustrating...I bought my daughter a new macbook and we set it up. it is logged on to the home wifi (fios) network but we get a message that says "not connected to the internet". I also have a macbook and mine won't connect to the internet either. we both can connect via cat5 though....
also, we both have ipods (touch) and they both connect to the network and connect to the internet.
what gives??? we did not make any changes to the router and I did not make any changes to my macbook settings and hers is a fresh install of snow leopard. I use snow leopard as well.
ideas would be really appreciated! thanks in advance.

give this a try.
go to the apple in the top left>system preferences>network. at the top of the window you'll see where it says "location" click on the pull down menu and select edit locations. in the new window click the "+" button and add in a new location, doesn't matter what you name it. click done and make sure the location is set to the new one and click apply and wait a few moments. you can do this on both computers. see if that works.

if that doesn't work then try this second.
go into the macintosh hd>library>preferences>systemconfiguration. take everything in this folder and put it ONLY in the trash, this will not work if you move it somewhere else. after you get it in the trash then restart the computer. when the computer comes back up reconnect to your network and see if you can get on the internet again. if that doesn't work then you'll need to call verizon and have them troubleshoot the router.