Try this to find your driver:
In Windows: Right-click "My Computer" -> Properties -> Hardware -> Device Manager
Now, right-click your wireless adapter, which will be under "Network Devices" or somesuch. Go to Properties, and poke around the tabs (I think there's one called "Driver") until you find a button which says "Driver Details." Click that, and it should tell you where the driver file is.
Copy it and any other files with the same name (ie, wg11v2s.sys, wg11v2s.inf) onto a flash drive or, God forbid, a floppy, and viola!