Commview WEP recovery - HELP!!?

I'm evaluating the security of my WEP key and my neighbour is letting me test his. I'm using Commview but when I find my neighbour's network, his wireless disappears from my network centre so I can't type in a key. How else can I receive packets whilst I'm searching the network. My neighbour's not very tech-savvy and says he can't help :S