wireless internet on both desktop and laptop required!!

I want to connect both my desktop and laptop computers to a wireless network. I have successfully connected my desktop to the wireless router, but i can’t with the laptop. I’ve managed to set up an AD-Hoc connection between the desktop and laptop, but I can’t disconnect the yellow cable (think this may be ether cable??) from the laptop – As soon as I disconnect the cable I lose the internet connection.

Is there a way I can have wireless laptop and desktop internet connections?

Please help – I don’t have a clue!!!