Vista - Internet installation problems

Hi all,
i live in italy and i bought an internet key to use internet where i live, but i have some BIG problems at the installation moment. Before Vista x64 i have had a laptop with XP, and the internet key works already perfectly on it. I want to install the software to use internet on Vista, and the official site of the internet key that i bought give me 2 opportunity:the 1st is to download a type of software (and when i run the installation and it is trying to install the drivers, it say: download drivers for plug and play devices, but i can't find them on the web) and the 2nd choice is to download another type of software that can't find the devices during the installation...
Is there anybody who can help me ?

Thanks
Pit

P.S.
Sorry for my english that's not very good.