Hi there Baldmancry,
In case a given HDD is not recognized by BIOS, then most probably there is either a connection issue or the drive is dead.
So, you can try the following things:
- Try the drive on another SATA port with different SATA and power cables. Make sure both ends of the cables are firmly attached.
- You can update your MOBO drivers and set it to default as johnnyb105 already suggested.
- If the previous two do not work, then I guess the drive is dead and you need to contact the manufacturer. You can be completely sure about that if you try it on another system and the drive is not recognized over there as well.
Cheers,
D_Know_WD