Cant format my 3tb drive to GPT

[coolNine11]

I am trying to install windows 10 on my 3tb hdd and I tried diskpart command and it says converted and I installed windows 10 on it but when I check in my device manager it shows me 700 or 750 gb hdd unused and my drive is MBR. Any help?

 

[PC-4LIFE]

In Disk Management are you able to extend the OS partition?

 

[t53186]

Read this first http://www.pcworld.com/article/235088/everything-you-need-to-know-about-3tb-hard-drives.html

 

[EDab]

MBR disks only supports 2TB hard drive in size, space beyond 2TB will be unusable. You need to convert it to GPT before you can use the rest.
as jefecito said, you need to enable UEFI mode before you can install Windows on a GPT disk