Check if the HDD is recognized in BIOS, if it is, then check the boot order priority.
And just a hint, if the BIOS doesn't remember the changes (or date/time) then this would be an indicator of a bad BIOS battery (usually a CR2032 one)
If the HDD is not recognized at all, then either it's gone bad, or your laptop's motherboard is malfunctioning.
Easiest way to check would be getting an SATA to USB adapter and hooking it up to another computer.