Can you see it in Disk Management? Has it been dropped or damaged in
any way? Have you disconnected it without using the "Safely Remove"
option?
There are several possible points of failure, including the drive
case, the cable and the drive itself.
It's also possible the connection between the case and the drive is
loose. I believe this is a SATA drive, and some of those cables are
not particularly secure.
If you can't see it in disk management, remove it from the case and
check the internal connector, or try another case or a USB adapter.



On Sat, Jul 25, 2009 at 7:09 PM, Ronald Smith<[log in to unmask]> wrote:
> Hello
>
> I have a usb hard drive for backup (WDC WD40 0BB-00DEA0 USB Device) which comes on when plugged in (blue light, vibrations), but does not show up in My Computer, despite appearing  in Device Manager and showing up as working and having drivers.
>
> This HD in its enclosure( Pluscom 3.5 IDE to USB 2.0) did show previously and was used to backup the C drive. But now it is absent from  My Computer in all three computers on which it has been tested.
>
> Why is it no longer recognized, and how can I restore it to use?

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