getting connected

I recently bought a used laptop and I can't get it connected to the internet. I don't know anything about networking so it might be something really simple I am doing wrong.

I know the computer is a dell. I have a wireless LAN adapter. When I turn the computer in it has a computer icon on the bottom right of the screen which has a red X on it. When I put the wireless LAN adapter thing inside of the computer there is another icon that comes on and it acts like there is internet connection just for a second. That computer icon doesn't have a X on it, when I put my mouse over it, it says there is no connection (i think sometimes it might say limited).

Both computers are windows. The computer I am on right now is a desktop. I have DSL through verizon. So there is a modem that I use to get connected to the internet on this computer. The laptop is Dell.

I do have a wireless b broadband router (linksys) that I bought a long time ago and never used it. Possibly I need to use something like that?

When I first got the laptop and I put that wireless card thing inside of it, a screen popped up asking me which connection to connect to and I exited off of it. I haven't seen that screen ever since.

Could someone help me? I have no idea how to get connected to the internet with the laptop that I have.

Thank you.