On the computer where the printer will be attached go to start, control pantel, printers and faxers, right click on the printer that you'll use, go to sharing, click the share this printer button, name the printer in the box to the right, click ok.
On the computer without the printer:
click start, go to control panel, printers and faxers, add printer, click next, click the button that says network printer etc, click next, click browse for a printer, click next, you should see your workgroup, click on the computert has the printer attached, and expand it until you see the printer, click next, a box will pop up , click yes then you should be able to print from both computers