USB drive enclosures shouldn't require special drivers.  I've bought cheap ones to expensive ones and use it as a portable device (so many different computers) and it always works :/  Unless you've stripped them from your Windows install, it should auto-detect.
Which device has the "?" next to it?  There should be a disk device, and I think there should be a USB device too.
If the Windows driver search thing can't find it, you could try a fresh install of Windows and see if it detects it (if so, copy the driver across).

One thing though, if you're not going to use it as a portable drive, why not just install it inside the computer?  Or you could use eSATA (faster) if you have a port on the back of the PC.

(This post was last modified: 31/03/2009 12:09 AM by ZiNgA BuRgA.)