I am assuming you have a router that you've set up to act as your local network. I have a laptop with Win 7 and the "main" computer (where the router/modem is) has Vista. I did this last year, so I know it can be done...I just gotta remember how.

OK, found what I was looking for. Here are two links that help - I used the first one, mostly.

http://www.microsoft.com/athome/organization/wirelesssetup.aspx

http://www.ehow.com/how_2012447_set-wireless-network.html

Good luck! Oh, and be sure to SECURE the darn thing with passwords, too.