Can't access Maxtor external HDD

I just got a Maxtor OneTouch4 Mini 250GB external HDD from my friend. It's worked fine for as long as either of us know, but it's suddenly not accessible. Everything seems to be working fine, but it simply won't show up on Windows; it's contently sitting in the fat dumb and happy state. Both ends of the USB Y-cable are plugged in, the disk spins up, the access light comes on and stays solid, both Windows XP and Vista recognize a new device and succesfully install it, and the drive shows up fully working in both device manager and the Microsoft USB device viewer utility. But I don't get a dialog asking me what to do with the drive and when I go to My Computer the drive is not listed.

I've already tried unplugging/replugging, restarting the computer, disable/enable and update driver via device manager, safely remove device, and checking for drivers on the Maxtor site (which has no drivers or useful information about the problem). This has all been done on two Vista and one XP machine with consistent behavior among all three, so whatever the problem is, I assume it's with the drive itself. The disk spins up with no scraping or crunching of platters, and the LED doesn't blink to indicate a physical problem, plus I've read two or three threads describing the same problem but I can't find any relevant information on how to fix this. By all indications the drive works, I simply can't get to it. Any ideas on how to go about fixing this? Thanks in advance.

Have a look at How to change drive letter assignments in Windows XP.

Is the drive visible in Disk Management?

Actually no, it doesn't.

This is a common problem, The drive spins with no unusal clicking or grinding. On some drives you can replace the hard drives mother board and access your data, but this is a shot in the dark. 50/50 chance. If your computers don't see the drive, recovery software is probably not an option.

Are you saying that the drive is not reflected in the lower portion of Disk Management as unallocated space?

Was the drive formatted when passed to you?

Louis

No, it isn't shown as allocated space. The drive was formatted presumably to NTFS when it was given to me, and my friend used it regularly with an XP computer.

If the only chance of making this thing work again is to mess with the hardware, then I'm just going to toss it. I don't have any data on it and my friend already had everything on another computer anyway, so it's not a problem if the drive is unusuable.