Can't partition unallocated space on 3TB hard drive
“I have a Seagate 3TB hard drive, and I install Windows 10 on it. However, I
forgot to partition hard drive at the beginning of the Windows installation. I used
Windows Disk Management to create two 1TB partitions, and I was trying to create a
third partition with the left unallocated space. But, when I right click it, I found
the “New Simple Volume” option is grayed out.
I recognized that MBR disk only supports up to 2TB, so I had a plan to convert
MBR to GPT disk. Unfortunately, the option to change hard drive to GPT is also
What should I do? Is there anyway that I can partition 3TB hard drive?”
Why you can't create a new volume with unallocated space on 3TB hard drive?
A MBR disk supports up to 2TB hard drive, which is the reason why your 3TB hard drive
only shows 2TB, and why you can’t create a new volume with unallocated space on 3TB
hard drive. No matter how big your hard drive is, you cannot use any space beyond
2TB. While GPT disk supports more than 2TB hard drive. If you want to partition your
3TB MBR disk totally, then you need to convert MBR to GPT disk before
Windows Disk Management allows you to convert MBR to GPT disk, but it requires the
disk must be an empty disk. Otherwise, it cannot be converted. Thus, you need to
delete volume(s) you have created before converting. Or, you can use AOMEI Partition
Assistant to convert MBR to GPT without losing data.
Note: GPT disk requires UEFI start mode. Before converting, you need
to make sure that your motherboard supports UEFI partition table.
Partition 3TB hard drive with AOMEI Partition Assistant
AOMEI Partition Assistant is a
great partition manager that can help you convert
boot disk between MBR and GPT. It is an amazing software that you can use to
partition your 3TB hard drive. Here is the specific guidance of how to create a new
volume with unallocated space on 3TB hard drive.
Step1. Install AOMEI Partition Assistant Professional on your
computer. Launch it. It will display you the basic environment of your disk(s). Here
you can see your Seagate 3TB hard drive with two 1TB partitions, and unallocated
Step2.First, you need to convert the MBR disk to GPT disk. Here,
right click the disk, select Convert to GPT Disk.
Step3. It will ask you if you are sure to convert the selected disk
from MBR to GPT disk. Click OK.
As you installed system on the disk, it will give you a note that you should make
sure if your motherboard supports EFI/UEFI boot. If not, your system will be unable
to boot next time. If it supports, clickYes.
Step4. Then, you will back to the main interface, and you will see
the disk has already became GPT disk. Click Apply to submit.
Then, click Proceed to execute.
Then, click Yes to confirm.
Wait till the proceed complete. Then, reboot your computer from EFI/UEFI
After the conversion, you can use AOMEI Partition Assistant to create a new volume
with unallocated space on 3TB hard drive.
1>. Right click the unallocated space on 3TB hard drive, select Create
2>. Then, you can specify the partition size, drive letter, file system, partition
type of your new partition. Click OK.
3>. Then, click Apply at the toolbar to submit the mission.
AOMEI Partition Assistant is such a great tool for partitioning hard drive. It
supports working with all Windows PC operating system including Windows 10/8/7. With
the help of AOMEI Partition Assistant, you can partition 3TB hard drive simply like
create a new volume with unallocated space on 3TB hard drive. Besides, it provides
you many other features such as resize
partition, split partition, and