usb unknown device

Hi. this is my first post and i really need some help. I've surfed the web looking for solutions but still no answers. Here it goes..

I've recently bought an external 80 GB samsung HDD. The HDD is inside a Q-tec box that connects to the motherboard through an usb port. The problem s that each time i plugged the cable i get an "unknown device" and windows does not recognize it as an HDD (or as anything else). I've looked in the mobo manufacter's (ECS) but i found no drivers. I also went to Q-tec website but still no answer to my problem. i am running XP SP2 and, from what I've read, there's a few peole with similar problems. Can anyone help?

Tkanks
Alex2005

Are you connecting the drive with an external power source attached? The usb port will not deliver adequate power for an external hd.

Do you have chipset drivers installed for your m/b?

Also are you conencting into the front case ports or the rear?

yes i have the drivers installed and i am connecting the HDD into the usb ports in the back (i don't have any in the front). the Q-tec box comes with an external power source.
the thing is that the HDD was working with windows 98, it was only when i formatted the main disk and installed XP SP2 (not upgrade) that the problems started. What drives me crazy is that this is the only device that isn't recognized! I also have a flashdisk that works perfectly in all the usb ports and, the external HDD is recognized in other computers with exactly the same software!!

Help!

Did you download the usb non critical update from microsoft after installing xp? and the latest chipset drivers?

i did not download anything from microsoft (apart from the automatic updates) nor the chipset drivers from SiS. the chipset is Sis 645 DX2 and there aren't any new.

btw: welcome to WD Alex.
Can you go into Device Manager and confirm that there are no "unknown devices" listed under USB, Disk Drives, and Human Interface Devices?

what I have is an unknown device listed under the usb controllers. I have no other conflicts and everything else works fine. I already tried to uninstall all usb controllers and put windows to make a scan for new hardware but still no improvement: the HDD is still an unknown device and it's the only thing i have plugged into the usb ports.