I bought a new laptop and cant wirelessly connect it to the internet forgot netw

Hello,
I recently bought a brand new laptop and I am trying to connect it wirelessly to the internet but it wont connect without me actually having my internet cable plugged in. My old computer worked just fine with this running vista. i forgot my network key and have no idea even what it could be or where to find that. Is there a way to get this figured out or reset my network key or establish a connection with the internet cable and unplug it so it knows that im not trying to sneak some internet. i find this all very dumb and frustrating. if im plugged directly into attempting numerous things over and over again youd think the computer would finally get it. Anyways, any help on this?