I'm running Windows 7 Ultimate 64 bit on a Dell M4500 lappy(quad core). I have an external hdd housing that I connect to via USB and all this while, was able to access 3TB hdds that were formatted on other machines without any issue. I'm trying to format a new 3TB hdd for the first time on my lappy but when it was connected, only 700+GB was shown. I already set it to GPT format but still same result. I'm planning to use this hdd for backup storage only. How do I solve this?