Hi @atlakeem ,
Check in ''BIOS > Startup > Boot'' and see if there is a HDD0 listing for the boot order.
If it is there try highlighting it (select it) and check if it shows up in a ''disabled'' list on the screen. If so ''enable'' it. I think that you do this by pressing Shift + 1 (the ! key) although I’m not 100% sure with your model that this is how to do it.
Hopefully this will restore the HDD in BIOS. When it has been disabled in the boot order it is no longer available to BIOS. This feature is for when people wish to use an external drive only and not have an internal HDD