George should go into BIOS and see if the connectors are even seen there. If they are, then he'll know the controller is working and it's a problem with the hard drive. If the SATA connector is messed up, that's a motherboard issue. Since he can get the drive to work with a PCI to SATA adapter though, it sounds like it's probably an issue with the SATA connector on the motherboard. George can always go to the motherboard manufacturer's website and make sure he's using the latest firmware.
Lawndog in the chatroom said to check that the SATA interface is even turned on in BIOS. George is a little nervous messing around in BIOS, but Leo said there's no real risk there. He can always reset to defaults.