Ususally when a HDD fails to appear in windows, it's because it's not partitioned correctly.
Since you can see it in BIOS and in windows install the drive is most likely functional.
Go to "Control Panel/Device Manager" and look under "Disk Drives" to see if windows can see the drive. If it's listed there then the drive needs to have a drive letter assigned to it for windows to be able to show it in windows explorer. If it's NOT listed then you probably have a bad drive, bad connection, or some other problem.
Usually when there is no drive letter assigned automatically by windows, it's because the disk is not partitioned. Open a command prompt and type in "diskpart". When the prompt changes to DISKPART> then type in "list disk". You will see all of your disks listed there. Determine which one is the second disk and note its' drive number(Most likely it will be listed as "Disk 1"). Type "select disk 1" and then "list partition".
If no partitions are listed then you will need to partition the drive and then assign a drive letter to get it to be visible in the windows explorer. If you decide to partition the drive, make absolutely certain that you have selected the correct drive first. You don't want to attempt to repartition your boot drive.
Here's how to do it (you're still in DISKPART>, right?)
select disk 1 (assuming your second disk is listed as disk 1)
create partition primary
As soon as you assign the drive letter the disk will appear automatically in windows explorer and you may see an autorun window appear as well. Once that happens, type "exit" , "exit" to close the command prompt window. Now you can right click the new disk and format and label it.
Try updating or reinstalling motherboard drivers, the other day, when doing a fresh install, my SATA III ssd worked fine, but my 2nd hard drive wouldn't show up in windows until installed current versions of SATA controller drivers.