Aspire acer 5620 no hard drive found but loads back up disks

So, you cannot find the main HDD or the back up drive at all in the BIOS? Even under the boot order? If that's the case, it sounds like there could be an issue with the motherboard/hdd connector going to the motherboard.

but why does it load back up disks from dvd drive ok dont understand that all files are on hard drive just will not restart becaause bios has no hard drive listed