With an always-on, high-speed Internet connection like DSL
(Digital Subscriber Line), a router is a prudent addition to your local
network.
It filters out unauthorized access to your network, which
prevents an intruder from accessing computers that are connected to that
network.
However, getting your computers, routers and modems on the
same page may not work right "out of the box."
There are a few things you must be aware of, especially if
this is a wireless network.
Unplug your DSL modem and D-Link router.
In order for the network to properly recognize its devices,
these devices must be attached in a specific order.
Plug in your DSL modem's power cord.
There is usually no power button on a modem.
Simply plugging in its electrical cable will turn it on.
Give your DSL modem a couple minutes to re-establish its
connection to AT&T's network before taking any further action.
Plug in your D-Link router's power cord.
Like the DSL modem, this router will probably not have a
power switch; simply plug in the power cable, and it turns on.
Let the D-Link router sit for a couple minutes while it
establishes its connection to the DSL modem and AT&T's network.
Physically attach your computer to the router with an Ethernet
cable.
Even if the router and modem are wireless, a physical
connection must be established to properly configure the router.
If this is not a wireless network, then your setup procedure
is essentially complete.
To access a D-Link router on your network, open an Internet
browser and navigate to the 192.168.0.1 address.
This will bring you to your D-Link router's interface.
The default User Name is "admin" (without the
quotes), and there is no password.
Enter the User Name
and click the "Log In" button. This will bring you to the Setup
window.
Refer to your D-Link router's documentation for changing the
default password (highly recommended) and forwarding ports.
If this is a wireless network, you have a couple further
steps.
First, change your network's SSID (Service Set Identifier)
title, so that you can recognize it when other wireless networks are nearby.
Also, choose your wireless encryption and passphrase. WPA2
(Wi-Fi Protected Access 2) is a solid option.
Specific instructions depend on your model of D-Link router;
so refer to your documentation (which can usually be found at the
manufacturer's website if you do not have it on hand).
Disconnect the Ethernet cable from your computer.
Your new wireless network should be visible with your
computer's wireless adapter.
Windows and OS X will notify you of networks in range when
your adapter is active.
Connect to the one with your SSID, and enter the passphrase.
http://www.microsoft.com/athome/moredone/wirelesssetup.mspx