Without knowing Operating System and specifications, a couple things that you can check.
1. On your Linksys do you have any security setup, for example WEP, Mac Address Settings etc.
2. If you move the card to your other laptop does it work?
Those would be the first couple of items I would try.
I have a working LinkSys router, powering a laptop with no problems. I have recently bought a wireless card for a second laptop and gone thru the set-up process. The laptop picks up a wireless connection fine from my office (have a hot spot there), but will not pick up available wireless connections at home, even when laptop #1 is not only picking my router, but also can see that my neighbors is available.
Can you offer suggestions on what I should check?