I harvested a number of hard drives from old laptops, including 3 x Fujitsu MHK2060AT 6GB drives. Two of these drives work perfectly well, the 3rd one is most peculiar.

I am running Windows XP Pro. When I plug it into my external drive enclosure, it gives off a piercing sound (from the disk itself) which sounds like the old Space Invaders game. When I look at Computer Management/Disk Management it does not appear in the drive list and it doesn't appear in the Safely Remove Hardware list either.

Does anyone have a clue what could be the cause of this behaviour? It sounds like a burglar alarm going off.

It sounds like the bearing is going bad, making the piercing sound. If it isn't showing up on the drive list, it could need to be formatted, but then again, it might just be bad and not registering. You might also try a different drive that you know is good in the external enclosure, just to make sure there isn't something wrong with the enclosure.

The enclosure is working fine with other drives.

Between the noise it is nice and quiet and sounds like a normal drive, it doesn't sound like its crashed.