Why second internal sata hdd is not recognized by bios

[unmesh]

Hello,
I have 1 SATA HDD of 160 GB , and i have connected second SATA HDD of 320 GB as slave hdd just for storing data.
First time when I connect it to my MB my computer start with windows in it (in second hdd).
and when I again restarted my computer n open my BIOS , it was not showing me second hdd as connected. It is not recognized by BIOS.
All the cables and power supply cable are perfectly connected.
Please help me.

 

[RealBeast]

Assuming the drive works (test it on something else to know) insure that it is on a sata port of a controller that is enabled in the bios.