Lead3

With the problem hard drive connected, go into BIOS and go to the Boot Tab. On Boot screen there should be Boot Device Priority and Hard Disk drives. If you look in Boot Device Priority, you will see the boot order. It will list all the boot devices. Does the problem device show in this list? If so you will need to change this to the original drive.

Edit: In your version of the BIOS, when you go to the Boot device Priority
select the Hard Drive line and press enter. This will give the list of hard drives. Put you original drive at the top of the list.