Win-Mac Printer sharing help needed

We have a home network with three Macs (an eMac desktop and two Macbooks) and one Windows machine running Win 7, with a late-model Airport Extreme as the network hub. The eMac is hardwired to the Airport via Ethernet, and we have a shared USB printer (it's a Brother). All three laptops access the network wirelessly. So, here is the problem: both Macbooks can print to the shared printer with no problem, but the Windows laptop can't. The user can get into the "install printers" dialog box and install the printer, but when she actually tries to print something, nothing happens: the Print dialog box pops up, and she can hit "Ok" to print, but nothing actually ever gets printed, and nothing even shows up on the print queue. What are we missing? Is the problem with how the network is set up, or is it a setup problem in Windows?

G;day and welcome to the forums.

First question has the Windows software been installed on that laptop and has a later version of the software been released for Windows 7? Would do a search but you have not included the Brother printer model. Usually Brother software for both Macs and PCs is first class.