Did your run your boot-camp utilities when you switched to Windows 7?
Boot-Camp should create a driver disk for such devices ( http://support.apple.com/kb/ht4407 )
With that out of the picture you are searching for the wrong thing.
With that out of the picture meat your new best friend: PC Wizard http://www.cpuid.com/softwares/pc-wizard.html
Install and run PC Wizard then, look at the first page. Search for the drivers to the wireless adapter listed.
If you are uncertain, goto File > Save As, and make a text copy of the page (default settings) and post it here.