The laptop did not want to boot properly and made a sound it has never made before. Thereafter, a system restore was required and there is no secondary hdd to be found under Disk Management or BIOS.
It does sound like a mechanical failure of the HDD. What kind of sound was it, grinding? clicking? buzzing?
Strange sounds followed by no response is NEARLY always hard drive failure unfortunately.
Try checking the cable of your second HDD.Clean and replug the cables connected to it firmly.
Have you ever restart your PC? If the computer could not boot up then I guess the only way you can do is to reinstall the system.
Not sure about this.
But a boot software may could help you to get your data out of your PC before you decide to reinstall.
I seemed to have ever met a software that may help you and you may find it here: http://www.easeus.com/data-recovery-wizard-winpe/
Do hope it can help you with your PC.
good luck :)
have you tried to reset cmos battery?
It sounds like hardware failure of the secondary drive. That is the usual cause when it does not show up in BIOS. If it does not show up there, it will not show up under Disk Management or Windows Explorer either (Windows queries the BIOS for hard drive information). Since it does not show up under BIOS, you cannot run other types of drive diagnostics to even find out what kind of failure it suffered. The drive will simply need to be replaced.