Hi. I think I can help you with this.
First, make sure internet is directly connected to the router with a lan cable from the cable modem.

Next, connect your laptop to the router's lan ports with a lan cable, instead of attempting to connect to it wireless-ly.

Next, open a browser, and go to this address: 192.168.2.1

Next, if you didn't assign a username and password, when it asks for them, leave them blank, and press enter

If you have already given it a username and password, use them to log into the router.

Then, go into security setting and select a security level...i.e. wep, wpa, and so on, and give it whatever you want to have for those, but make sure you write them down, as you will need them to log into the internet, as well as logging into the router page.

After you do everything you need on settings, click the save button if there is one.

If not, then click log-out

Next, disconnect the wire from the router to your laptop, and unplug both modem and router.

Next, plug in modem first, and wait 45 seconds for it to initialize, and then power up the router.

Within about 30 seconds or so, it should initialize, and be ready for you to use it.

Thenlog on to that internet connection, and enter the username and password that you gave the connection, and you should be good to go.