Probably the easiest way to configure your machine is:
ou need a flash/pen drive or memory card with reader.
I assume we are talking xp ?
Start/Control panel/Wireless network setup/ and follow the onscreen prompts.
Using a flash drive is quick and you will have to insert the flash drive to any machine that needs the host pc settings.
Alternatively,open your routers configuration page and look for security and WEP/WPA this will hold your encrypted key.If not accessible,you may have to create another key code and transfer that to the other computer.
What router are you using Make/Model please.