Allow me to clarify.
There is no external driver that you need to download and install on your PC to have your PC recognize the phone. If it cannot recognize it and install the proper internal USB driver, chances are, you are either using a bad cable, OR, like on my high-end DELL Laptop which runs XP (32bit), I have success ONLY when I use a USB1.1 port, like that replicated on my USB keyboard or LCD displays that I use with the Laptop.
Now then, you have alternatives. May I suggest two.
Download SwiFTP from the Market to your phone, and an FTP client for your PC from the web (like FileZilla or equivalent). Use FTP to move files back and forth.
Download MyPhoneExplorer from the Market to your phone, and MyPhoneExplorer client for your PC from the web. Open up your Firewall so the ports used by the phone and program are not blocked (Google it).
When people are telling you the drivers on Samsung's site are for tethering, what they mean is these are Modem drivers. Don't install these!
Good Luck.