Accessing the internet with wireless laptop

My friend has a computer connected to the internet and she also has a wireless router that connects to her laptop. Her laptop shows a good connection to the router. The router is a linksys and so is the card in the laptop. I connected the cable modem to the router then from the router to her pc. with that being said shouldnt the laptop be getting the internet?

Some cable ISPs register the MAC addresses of PCs connected to their modems. If this is the case with your friend's ISP, you will either need to register the router's MAC address with the ISP or clone the PC's MAC address (if the router supports this feature).

hi there,
how is the router connected to the cable modem, that is my first question, is it a usb connection or a normal LAN connection using a RJ45?
you need to check if NAT is available on that router, if not then eve though you might have a excellent connection from your laptop to your router, you will have no connection to the internet.
try to ping the cable modem using its IP address, see what the response is. if you are able to ping it with a good response rate, then definitely check the router for NAT availability. if you are not able to ping it, then the router is not seeing the cable modem.
let us know what IP addresses are for the following:
Cable Modem = ??
Router = ??
Laptop = ??
knowing this information will help in troubleshooting