The hard drive shows up in 'Device Manager' - but does not appear in Disk Management. Even the 'unallocated disc' stopped showing up.l The external hard drive is a new - seagate expansion. Any thought?
If it is new, I'd consider just returning it for a warranty replacement. It sounds like Windows is seeing the USB bridge (the card that converts the connection from USB to the SATA hard drive inside the enclosure) and not communicating with the physical hard drive.
The hard drive shows up in 'Device Manager' - but does not appear in Disk Management. Even the 'unallocated disc' stopped showing up.l The external hard drive is a new - seagate expansion. Any thought?
If a different USB port or different USB cable does not fix it...send it back.