Asus M599X not recognizing 1TB HDD

Solution
If your first boot was with the HDD connected, try disconnecting it. Then boot to BIOS, set your boot priority to USB or optical drive, whichever you're going to use for Windows install, save and exit, then power down.

Reconnect your HDD, make sure your power and data cables are firmly seated at both ends, then restart and see if it takes. If it doesn't, try connecting it to a different SATA port.
If your first boot was with the HDD connected, try disconnecting it. Then boot to BIOS, set your boot priority to USB or optical drive, whichever you're going to use for Windows install, save and exit, then power down.

Reconnect your HDD, make sure your power and data cables are firmly seated at both ends, then restart and see if it takes. If it doesn't, try connecting it to a different SATA port.
 
Solution