I have a laptop running Windows XP and I recently bought an external hard drive for it. Not liking the case that it was in I went ahead and bought a new one. When I plugged everything up and started the hard drive up again (in the new case) my computer wont read it. Im using a USB connection. When I start it up my computer makes the noise that it has found a new device but 5-10 secs later it makes the same noise to say that it has been unplugged. Also the hard drive does not show up in any of my system trays. I put the hard drive back in the old case and it ran and worked fine. Is it a bad case or do I need a different driver?

Could someone please help.

If the new enclosure came with a driver disk, you might try that. A smartly designed external enclosure will present itself as a standard removable drive, which XP supports rather well. It may be that the drive that came with the first enclosure has something special about it; are there any jumpers that might be adjusted?