By Cherry / Last Updated February 22, 2019

The Scenario

"I have 3 TB hard drive, and I installed it on my Windows 7 computer. There are four parts on my hard drive, the system reserved partition, system partition and two unallocated space, and I want to use the unallocated space to create some new partition to store different files. However, when I right click the last unallocated space, it showed gray like the following picture displayed (the first unalloacated space is valuable)."

New Simple Volume Grayed Out

It was too bad that the New Simple Volume, New Spanned Volume, New Stripped Volume, New Mirrored Volume, New RAID-5 Volume greyed out so that you cannot create new partition with this unallocated space.

Another user said that his 3 TB disk only used 2 TB like the following screen shot, and he tried to use the New Simple Volume to create a new partition to use it. However, he found the option greyed out.

3TB Hard Drive

With those kind of problem, how could you make a full use of your disk?

Why "New Simple Volume" grayed out?

As the scenario said, the first unallocated space is in normal state, while the options in the second unallocated space is grayed out. Why? Most of users may know that Windows operating system supports both MBR and GPT disk, and the two disk types have their own characteristics to effect on their performance.

MBR, the abbreviation of Master Boot Record, which only supports the capacity up to 2 TB, and you can only create up to 4 primary partitions, once you want to create more partitions for different files, you have to convert one primary partition to extended partition.

GPT, the short of GUID Partition Table, breaks out the limitation of MBR. It supports more than 2 TB capacity and you can create 128 partitions on GPT disk.

Considering of the problems in scenario, the problem is clear that your hard drive is MBR that can only use up to 2 TB. That’s why the New Simple Volume greyed out beyond 2 TB in Windows Disk Management.

How to solve New Simple Volume greyed out?

To solve the New Simple Volume greyed out, you should change the MBR into GPT disk so that the part beyond 2 TB can be available. And here provides you two different ways to convert MBR to GPT disk.

Method 1. With built-in Disk Management

Disk Management is the build in disk manager of Windows system. Right-click This PC -> Manage -> Disk Management, then, right-click the 3TB hard drive and select “Convert to GPT Disk”, then follow the guidance to finish this conversion.

Convert to GPT

However, when you want to use it to convert disk from MBR to GPT if there are some files on the 3TB hard drive, you have to delete all the data on the disk. Because Disk Management can only convert an empty MBR into GPT. Otherwise, you’ll find Windows Convert to GPT greyed out.

Convert to GPT Greyed Out

Method 2. With AOMEI Partition Assistant

AOMEI Partition Assistant is a powerful disk manager. You can use it to manage your disk for Windows XP/Vista/7/8/8.1/10. What’s the most important thing is it can convert MBR to GPT without losing data.

First, you need install and launch AOMEI Partition Assistant Pro, you will see the main situation of your hard drive. To convert MBR to GPT, you can right-click the disk no matter there are partitions on it or not, select “Convert to GPT Disk”, you don’t need worry about the data because it can convert MBR to GPT and vice versa without losing data.

Convert 3TB MBR Disk to GPT

Then, it will pop out a window that you can ensure whether you’d like to convert it. Click OK.

OK 3TB Disk

After that, the 3TB hard drive will be in the GPT statement, but don’t forget clicking “Apply” at the tool bar. Then, it will convert MBR disk to GPT disk.

Apply 3TB

After converting the MBR disk to GPT disk, you can make a full use of your 3 TB hard drive. The New Simple Volume of Disk Management would not be grayed out, so you can use it to create new partition or extend the partition before. You can also use the AOMEI Partition Assistant to create partition, merge unallocated space, and so on.