Yeah it's not that hard, Windy.
Just pop open command.exe. Start-Run-cmd. After you get into the command prompt, type ipconfig and figure out your IP. That's the ip of the router.
From there, type it into a browser (the IP), and you should reach your router configurations. Go to the one that allows you to modify MAC addresses. The DS has a MAC address built into it, look for it in the connection config on one of your games. Include it in the MAC addresses to be allowed through and you should be good to go.
Or you can configure your DS with all of the info into the DS itself, putting in the IP manually and such.
If this doesn't work, check the official website for the Nintendo WiFi and see if your router is compatable with your DS. If not then tough nuggets...
Hope this helps, Wind.
Reality swirled in a wholly blue manner, revealing absolutely nothing of merit. Things flashed madly in and out of existence like some entirely other sort of phenomena. On a whim, Kurt Vonnegut imploded, taking a sizeable hunk of Massachusetts with him. However, seeing as Massachusetts wasn't entirely sure it existed, the chunk wasn't all that big.
*cough* please refrain from bumping when a PM could do it and what you said is already noticable.
But you should know this by now <_<