The wireless adaptor on your laptop IS a NIC. So you have nics on all your computers. You need to ensure that both machines are members of the same workgroup. Then you need to enable sharing.
First, on each of the machines, right-click "My computer" and choose properties
On the Computer Name page, check that both have the same name for the workgroup - it doesn't matter what the name is, as long as it's the same on both. If not , click the Change button and type a new name in the "workgroup" section. You will need to restart the machine.
Now that both machines are members of the same workgroup, on the PC, right-click the printer and choose Sharing. Click on "Share this printer" read the bit about drivers and take the appropriate action.
On the laptop, double-click "My network places"
Double-click Entire network
Double-click Microsoft Windows Network
You should now see the name of the workgroup that both machines belong to Double-click it
Locate the shared printer on the PC and double-click
Follow the instructions from there...