Windows 7 - Windows cannot find printer on wireless network

I have a Macbook Pro that I just loaded a clean install of Windows 7 home 64 bit using bootcamp. I also have a canon printer. I loaded the printer's software in Windows, using a USB cable connected directly to the computer. The printer prints fine. But normally I have the printer connected to an Apple Airport Express wireless network, which prints fine from the Mac side of the computer. Windows see's the Airport Express wireless network and it connects to it fine. But when in Windows and I try to print a document, it can't see the printer. The printer says it is offline. How do I make Windows locate the printer?

What Canon printer do you have? Normally if you have a network capable Canon printer, and you already have it configured for wireless printing, you don't connect your computer to it via USB to install the necessary drivers.

It's a Canon Pro 9000 II. I followed the installation instructions exactly, that came with the printer and it said to connect to directly to the computer with USB.