I bought an Alienware 15 r2 recently and I am having some issues with my hard disk. It comes with a 512gb ssd (with the OS) and a 1tb 7200 rpm hard disk. When I turn the computer on 1tb the hard disk is not detected in the windows but it is present in the BIOS, when i restart the computer the disk is present and it functions normally!! On changing the hard disk mode from RAID (the default) to AHCI mode the problem appears to have solved but the same happens everytime I go back to RAID mode. I know there is no connection with that but the horrible customer care is not able to fix this issue and they have issued me a motherboard replacement. But the same thing still happens!