Can't install WNDA3100

I'm trying to install a wnda3100v3 adapter on my desktop computer. During the install the instructions ask me to insert the adapter into a usb port. I do this but the install software cannot find it. I have tried several times including uninstalling and reinstalling the software.Unfortunately, I am running XP and need it to support some old software I have. I installed the adapter on a lookalike desktop about 2 years ago and it has always worked fine. Anyone have an idea?