forgotten WEP code

I had an Inspiron hooked up to my Dell router but it crashed. Now I am trying to hook up a new computer to it but my wife threw away the paper with our WEP code on it. I thought I remembered a way to figure out what the WEP key is but I can't find it anywhere online.

 

I may have also used a passkey in an attempt to make it easier to remember. Would that matter at all if there is a way to access the programmed WEP key?

 

Thanks

 

Jeff