Is your Desktop connected to your ADSL Modem/Router same as your
Laptop? If so then there is no need to do anything except to make sure
that on your Desktop you have enabled Files & Printer Sharing.
You could use Network Wizard to help you out or please post your
question on:
news://microsoft.public.windows.networking.wireless
I can't give you instructions here as it has nothing to do with Office
Setup and others would be entitled to censure me!.
Thanks.