Right if the drive has an external enclosure.
And the drive inside of it is a 3.5" desktop drive.
The reason why the drive spins up, but the drive does not register as connect to the system with windows on it.
And the external drive uses a usb connection for data.
Plus it`s own power brick connected to the external drive enclosure.
Is because in most cases the bridge board inside the external drive enclosure, that converts a standard desktop Sata drive of 3.5" to a Usb data cable connection has failed Mesu41.
To get the Data off the drive or to be able to read the contents of the drive, remove it from the external drive enclosure.
Once open if the drive is of the 3.5" form factor size you will see the bridge board.
And by removing it you will be left with a standard Sata data cable, and power cable connection of the drive.
Simply connect the drive to your system via a Sata data cable and to a sata port of the motherboard, and then connect power to the drive also.
I have seen this plenty of times where the bridge board used in an external drive enclosure fails.
If you follow the instructions above the drive once connected via it`s native Sata connection of the physical drive with power added to it will work and let you copy the contents of that drive to another drive.
Or just leave it in the system you connected it to for the time being.
And buy another external drive enclosure for a 3.5" sized drive.
The bridge boards always seem to fail first other than the physical drive it`s self F.Y.I mesu41 ok.
2.5" inch drives in an external enclosure are a bit more of a pain.
Because they use a control board on the drive its self that connects via a soldered on Usb port.
If it fails and you cannot read any information off the drive then it can be hard to fix or repair.