Dell TrueMobile Wi-Fi Card Not Recognized

I use a Dell TrueMobile 1300 USB Wi-Fi card to connect to the internet.
Recently, I reinstalled Beta 2 to free up a large portion of my HDD.
Before, the card worked fine, although it took some effort to get it to work.
Now, the card is not being recognized by the driver software I downloaded,
and the OS lists it as an "Unknown Device".

I copied the driver files from my old installation before I wiped the HDD,
and tried installing those onto my new installation. The software was able
to install correctly, but it was still unable to detect the card. In
addition, when Vista prompted me to find driver software, and I told it where
the software was, it failed to find any compatible software. I have tried
running it in compatibility mode, plugging the card into different USB ports,
and contacting Dell support, to which nothing worked. (The guy at Dell
thought my (2005 Dell Dimension 3000) computer was incompatible with Vista,
even though everything is running fine)

Thanks for any help you can give!