Your problem is that, your disk must be initialized as MBR disk, as we know MBR disk could only support 2TB storage disk, if you want to use the disk which is larger than 2TB, you must initialize it into GPT disk.
Here you need something to note:
First, if you want to boot system from a GPT disk, your motherboard must support UEFI mode. The bios could not support boot from GPT disk.
Second, if you want to convert MBR to GPT disk, you need delete all the partitions first, then re-initialize your disk. Or you need to use other software (as I know there's no free software could do this).
Here is an video tutorial about how to convert MBR to GPT without losing datahttp://www.youtube.com/watch?v=hlYjNbiVB-0