Well, does it have a UEFI bios? I think it probably doesn't. So that means, that you cannot boot off of a HD that is larger than 2TB.
However, with OS support, your OS can handle drives larger than 2TB as data-only drives.
Don't forget, when Windows asks to "Initialize" the drive, choose GPT, to utilize the full capacity of the drive.
If it doesn't offer you the choice of GPT, then something is wrong, or your OS doesn't support it.
Windows 7 supports GPT for certain. I am unsure about other prior Windows OSes.
