Windows Vista security key

I am setting up a wireless network with my brand new HP Pavilion DV9700T (Intel PRO Wireless 4965AGN w/Bluetooth) and the D-Link DIR-655 router. I'm setting up the router through my existing desktop PC (custom-built five years ago).

Setup was easy, everything went fine until I tried to connect to the network with the notebook. I don't have the security key that Vista is asking for. It appears I was supposed to get this during the router setup, but I don't recall seeing it. And I couldn't find it in the web-based configuration page. Is there a way to get this without having to set everything up again?

And in a related question, I know that I can set Vista so I won't have to enter the security key every time I log on. But what about visitors who want to use my network? Can I create guest accounts so I don't have to give out the security key? Or even create a password for my own laptop that doesn't require memorizing a long security key?

I know these are pretty basic questions but the manuals I've read so far are still a little over my head at this point.

 

Wireless settings (on the left) ---> Manual Wireless Network Setup (button at the bottom) ---> Wireless Security Mode

The key is obscured with *******s, so come up with a new key (use WPA or WPA2, at least 20-30 characters for the key (no dictionary words like "tomato" or "password"). You might want to write this down. You'll need the key for every device.