First you need a wireless CABLE router not ADSL.
All cables are straight connections NOT crossover.
Start with everything powered down.
Disconnect the cable modem from the computer.
Connect the WAN/Uplink socket of the router to the cable modem with a normal Ethernet cable.
Connect the computer to one of the LAN sockets on the router with a normal ethernet cable.
Switch on the modem and wait for the lights to settle.
Switch on the router and wait for its lights to settle.
Finally boot up the PC.
This link may be helpful click here.
Once you have an Internet connection you can see about setting up the wireless side of things for your laptop.