1) Verify the wireless nic is even recognized by your laptop (Start -> Control Panel -> Network Connections). Should see something about Wireless.
2) Check your IP settings (is the NIC provided an IP, etc?): Start -> Run -> cmd [Enter]
You should see some stuff go by. Hopefully something like: "IP Address. . . . XXX.XXX.X.X"
3) Ping that IP Address by the command prompt
Should see some stuff like:
Reply from XXX.XXX.X.X: bytes=32 time<1ms TTL=128
4) Ping your router ("Default Gateway" from Step #2)
5) Ping your WAN IP Address. This is the address your ISP assigned to your Router, you will have to log into your Router (web-based usually) and find it (typically "Status" page somewhere)
Those 5 steps will verify that you 1) are assigned an IP address 2) can ping it 3) can ping your router 4) can ping through your router.
If any of those steps fail, then you know where to start. If they all pass, hrmm..