Where to enter a WEP key on Windows 7?

Hi.

I just bought a new PC and when I first started it, I was requested to enter the WEP key to my house network.
I didn't had the key with me, so I chose to do it later.
Now, when I try to connect to my network, I don't get the option to enter the key and it just says that I can't connect.
I am loosing my mind on this!! I looked into forums, and people answers to delete the network in the Share panel, however it does not appear so I can't delete it.

Help please!!

2011-07-31T09:51:56Z

When I right click, I only get the "Connect" options, nothing else.

TECH2011-07-31T09:39:56Z

right click on your wireless connection , and then go to advanced , there will be a empty field which has network key , enter your key here and then it will use and recognize it . otherwise delete any recognize network , and then turn your wifi off then on again ,. and the original popup for networks will appear again