To conect to wifi, you'd need to buy a WI-FI USB connecter.
They can be found at most video game stores for $37.00 (varies on location)
They get plugged into your USB port on your computer, then they enable you to
connect to wifi . If you have a Laptop the USB port should be found on the
side.
If you just need more information off of what I've given you, read the bottom
of my post for a recommended website for Wi-Fi.
When you get a USB connecter:
On your DS:
Once you have it plugged in, turn on your DS with a game that is compatible
with Wi-Fi. In the game there should be a place where it allows you to adjust
your Wi-Fi settings.
When you select that, two options should appear, tap on the one that is labled
"Nintendo Wi-Fi Connection Settings" You'll see four options to chose
from, you want to tap on the one near the bottom of the screen, it's shown as
"Connect To Your Wi-Fi USB Connecter." The next screen will say for
you to install your Wi-Fi connecter software to your computer
On your computer:(you must have internet connection on the computer)
Close your DS for now and turn your attention to your computer, insert the USB
into the the USB port on your computer. The picture that is next to the port
will look like this:
Install the software first, then a window will appear after the installation.
Ignore it for now, and look back to your DS.
On your DS:
It should still be on the same screen you left it on unless your battery is
dead (not recommended to conect to wi-fi with low power )
Tap "Ok" on your DS, It'll then launch a test connection. Look back
at your computer screen now.
On your computer:
The box I told you to leave alone before will still be on, and now it should
have your DS name inside it. Your DS name is what you entered your name as on
your DS configuration settings.
Click on your DS name and select the option allow access. You can either allow
or deny anyone access to connect on wi-fi through your USB.
On your DS:
Now that you have allowed access to your self on the computer, you can get back
to your game and tap on "connect to Wi-Fi" this time instead of
tapping "test connection." You'll then get a friend code that will
allow you to interact with others who have connected with the same game.
Notes: For more about getting started,connected, and swapping friend codes,
view this site:
http://www.nintendowifi.com/global/AboutWIFI_DS.jsp
Also, if you've ever heard of a Wi-Fi hotspot, that just
means you have to take your own computer or laptop with Your own Wi-Fi USB
connecter to the certain area for free Internet service. This only means public
areas, like at Starbucks or Panera Bread Compay, but then if you're doing this
at a friends house then you just need to get your self registered access on
their USB.
