I have a 250gb internal Ultra ATA hard drive enclosed in a 2.0 Usb external case. I installed it and did the formatting and was displayed that the formatting was not complete. I have not been able to re-format the disk or do anything else. My computer does not recognize the drive but I can locate the drive on the control panel where I can "safely remove items." I am running windows xp2 on HP computer originally 40gb SATA. The package instructions said to leave the external drive on master so I left it at that. During formatting and initializing I was able to name my new drive as k:. I have read several other threads with my same problem but none of them mention how to fix it when it is not recognized in disk management.