HDD recognized by BIOS but not by Windows

[Clumulum]

Hi everyone,
I have a Seagate Barracuda 3TB HDD that is around 3years old. This morning it just randomly dismounted from Win7 and has not been recognized by Windows again (Not shown in diskmgmt or device manager). The BIOS however recognizes the HDD and shows the correct name and capacity, etc. I tried putting it in an external case, but Windows only shows it as Unrecognized USB Device. The HDD itself spins as soon as it is connected to power.
Is there anything I can do to recover the partitions on the drive?

Thanks for your help,
Clumulum

EDIT: I just saw that when I plug it in as an external HDD, it gets recognized with both Partition for a second before it disappears again. Does that mean there's any chance I can recover my data?

 

[n0ns3ns3]

beside trying it with other computer, you have not much to do to troubleshoot it.

 

[SuperSoph_WD]

Welcome to the community, Clumulum!

I'd second what @n0ns3ns3 mentioned and advise you try the HDD on another computer just to see how it will get recognized via SATA. Great job with the troubleshooting and getting properly recognized from the external enclosure/docking station. If the HDD disappears randomly again, then you should definitely try performing more troubleshooting from another PC (internally). I'd also suggest you go to Disk Management in Windows to see how the hard drive appears there as well.

You might also want to check the warranty on the drive from the HDD manufacturer's official website. If it's still covered, you should be able to get it RMA-ed and replaced.

Keep us posted with the troubleshooting, though!
SuperSoph_WD