Unspecified External Drives after upgrading to Windows Vista

My system has Windows 2000. I am getting a cheaper upgrade of Windows Vista. I asked my friend to upgrade it. After that there are tons of new problem started appearing. The first is the external drive which failed to appear. It is not detected at all. I can see it in Device Manager listed as unspecified device. I tried to run a driver update but nothing worked. I changed port, cable, and performed windows update. But still no hope. I though this usb drives works quiet easily in all Windows edition. They why does it is not detected.

I am having a Vista Business Edition laptop. It is a new one that I had purchased sometime before. I am having a desktop also that has Windows XP. I purchased WD drive to copy my data. I got exactly the same issue in Vista, while the same on Windows XP works great. I checked drivers and different stuff but nothing worked. Later on I downloaded the drivers from official WD site. There was a update provided for Vista. Luckily my external drive started and I can copy data. Check the vendor site for some new driver updates.