If your second hard drive show up in bios which mean is pc know your have 2 drive.
But in windows please right click my computer and click manage.
The go section where Disk Management.
If you can see your second hard drive with colored black.
Please right click and format the hard drive after that you will see in my computer and you can start use that hard drive.
If you already did this step and still can not use hard drive...
TT,.TT other Pro user will answer this question sorry.