lol, at least you are now trying to keep up with technology
You have to get into your router config. To do this you usually open up internet explore on your PC. In the address bar type in....i am not sure at this point what you need to type in because of the router you have but try these. Type them in one at a time until you get one that brings up a username and password prompt.
192.168.1.1
192.168.0.1
192.168.0.0
192.168.1.0
Hopefully one of those will work. Once you get the username prompt box type in admin for the pass, nothin in the username. If that doesn't let you in type admin for username and pass. If that doesn't work try admin for username and nothin for pass.
Now if you get in you need to find a WEP section, i have no clue where it is, hopefully someon else around here has the same router as you and can help further. Anyways, once you find the WEP section you need to copy down the key code. There are usually 4 of them to choose from but you have to make sure you pick the one you have selected. The key code will probably be about 20+ characters long, so write it down exactly as you see it on a piece of paper.
Let me know if you get this far and then i will help you put the code in your x3i.