Can you post the output of ipconfig /all on both machines?
As for whatismyip.com, that only shows you the IP you currently have from your ISP, and this is on every machine the same.
It is the IP under which your Router is accessable from the outside.
Are you talking about the 2 different configs for the WLAN?
You can have as many configs as you want, but you would need one which has the same settings as your router, otherwise you can't get a wireless connection.