Computer wont boot past bios checks with hd attached

[mangoliciouse]

Ok a working 500gb Western Digital Hard drive of mine just stoped working. It was in an external network case (unknown brand). I took it out and put it in my computer and still doesnt work.

You can hear the hard drive spinning but when the bios starts checking IDE devices the spinning speed starts becoming random and then when that harddrive is called up it stops, which prompts my computer to stay IDE error and stops it from booting.

Please someone suggest how to fix it as I have alot of important data on there. Thanks.

Craig.

[ApPy10]

Is it making any clicking noise when it rotates?
it might be corrupted & if it is in warranty then you can surely get another hdd for free from the company.

[mangoliciouse]

It doesnt click it powers up and spins.. then when the hard drive checks occur it powers down and up a few times then just goes. and its not the hard drive im worried about its the files on it.