File Sharing Works but no Internet via WiFi

Alright this is my first post! Hopefully I can get some help here.

Problem
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I recently wiped my gf's computer clean. Previous to that her internet via wireless was running fine. When I brought it over to her house and installed all the drivers ect ect the internet would not load.

The Setup
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There are 2 computers. There is a wired computer which connects to a linksys wireless G router which then connects to her cable modem. Her computer has a linksys wireless card which connects to the linksys router downstairs.

I enabled filesharing on both computers and was able to move files back and forth between the two computers. I installed this small monitor system that linksys has and it displayed that her wireless computer and the router were communicating but the router and the internet were not. The weird thing is her wired computer downstairs CAN connect to the internet just fine.

I don't know too much about wireless internet and trouble shooting but I tried for about 6 hours the other night, 1 of that was spent on the phone with the linksys people. They weren't much help. They did say it may be a DNS issue. If anyone would like to leave some steps for me to follow to resolve this rather annoying issue I would greatly appreciate it! Thanks!

FYI:

She has AOL Broadband (I always give her a hard time cause of that) but she had to install the AOL browser for her to have internet! That's just messed up. I connected her computer via a cat-5 cable and I connected fine with IE(Avant Browser). I wonder what is so special about the AOL Client that lets her connect?