i like the linksys hardware, but find the software/firmware/utilities kinda flaky and not user friendly. in the utility you use now to connect to a wireless router, there is a profile created, or partially created that dosen't have the proper information to connect with your router and send packets across the net. it could be a static ip address with the wrong gateway, or dns server, or also a wrong or missing security encryption key, (usually wep), providing you have one. try this
1.start>run> type in "cmd">hit enter. a "dos" box opens up, type in "ipconfig" then hit enter, you should see a bunch of network info. could you please tell us what >ip address>subnet mask>gateway> dns server address are?
2.go into utility , view profiles, select and remove or delete your router from the list, then go through the process of adding yourself another brand new profile. you should have your tech savy friend there to help you out.
3. maybe try downloading and running this file, it replaces some reg keys and resets the host file on your computer, this could possibly help, and it only takes seconds to run it. http://www.snapfiles.com/get/winsockxpfix.html