I'm pretty sure that my BIOS is set to Legacy boot. I've checked my C drive and it's formatted as MBR. If there is an asterisk against your C:\ drive (normally 'Disk 0') then you are using a GPT UEFI/BIOS, otherwise it is MBR. This lists the drives attached to your computer and the right hand entry is headed GPT. To find out what you have open Command as Admin and type 'Diskpart' at the prompt, then 'List disk'.
If your computer is running a UEFI/BIOS then if your Windows system is setup as GPT then this limitation no longer applies. You can use larger discs but they would need to be partitioned into chunks of not more thatn 2 TB each because of addressing limitations within the MBR system. If you use a traditional Win 7 set up with an MBR structure then the maximum drive size you can access is 2 TB. Whether or not your computer can use HDDs of that size depends on how your computer is set up.
