Solved: Convert to GPT Greyed Out Server 2012

May 31, 2018

Sometimes you need to convert MBR to GPT server 2012, but you may find convert to GPT greyed out in Disk Management. You can refer to this article and learn how to fix convert to GPT greyed out server 2012.

MBR and GPT in Windows

MBR and GPT are partition styles used on hard drives. A master boot record (MBR) is a special type of boot sector at the very beginning of partitioned computer mass storage devices. MBR disks use the standard BIOS partition table and support up to four primary partitions. And GUID Partition Table (GPT) is a standard for the layout of the partition table on a physical storage device used in a desktop or server PC, using globally unique identifiers (GUID). GPT disks use unified extensible firmware interface (UEFI). It sustain 128 primary partitions and more than 16 million TB. Compare with MBR, GPT has better compatibility.

If you plug in a new hard drive in Windows for the first time, it will ask you to initialize the hard drive to MBR or GPT. Generally speaking, if the hard drive is larger than 2TB, it is better to be initialized to GPT. Otherwise, you may find the disk larger than 2TB not showing full capacity.

Why does convert to GPT greyed out server 2012?

Cause MBR disk support up to 2TB hard disk space and four primary partitions while GPT disk sustain 128 primary partitions and more than 16 million TB, and now our hard disk is getting larger, sometimes we have a partition larger than 2TB, but the traditional MBR partition table does not support, how to do it? At this time, we can convert MBR to GPT. Thus we can build more partitions or take full use of disk space.

As we all know, Disk Management is a built-in partition tool of Windows that enables you to convert MBR to GPT disk. But sometimes you go to Disk Management and right click the MBR disk, you may find the option “Convert To GPT Disk” greyed out in Windows server 2012. Why? The main reasons of you cannot convert MBR to GPT are as follows:

  • The hard drive is not an empty basic disk - There still has partition exist on the disk. Disk Management only support convert empty basic disk to GPT.

  • The selected hard drive contains system files - You have no choice but to back up all the data on the hard drive includes uninstall the system, but Windows does not allows you to do this.

Best convert to GPT software

IF you convert MBR to GPT with Disk Management, you must make sure that the hard drive you want to convert is an empty basic disk. And make sure it’s not contain any system files. Before you do this operation, you’d better backup the data on the disk to avoid data loss. If the hard drive you selected is not an empty disk or contains system files, the convert to GPT will greyed out. The best way to solve convert to GPT greyed out is convert MBR to GPT with the help of a powerful third party software. Here I highly recommended AOMEI Partition Assistant Server Edition - a powerful disk convert tool which provides you many powerful functions like Convert to GPT. What’s more, it is a lossless data operation. You can convert MBR to GPT easily and effectively without data loss. You can convert system disk from MBR to GPT directly, too. Besides this function, you can create/resize/merge/format partitions, convert primary partition to logical drive, change partition type ID and so on. Migrate OS from MBR disk to GPT SSD or HDD are supported too.

Solve convert to GPT greyed out Server 2012 with AOMEI Partition Assistant Server

The step by step guide to convert MBR to GPT are as follows:

Step 1. Install and run AOMEI Partition Assistant Server. Right-click the disk you want to convert and select ”Convert to GPT Disk”.

Convert to GPT Disk

Step 2.Then, click “OK” after confirming the operation.

Click OK

Step 3. After that, it will back to the main console, and you can preview the partition style. Click “Apply” on the toolbar to commit the operation.

Apply Convert to GPT

Step 4.Then there will be a pop-up window, please click “Proceed” to commit the operation.

Finish Convert to GPT


  • For conversion between MBR and GPT disk on PC , you should make sure the power supply is sufficient.

  • Don’t abnormally terminate the program during the conversion to ensure the data is consistent.


Follow these simple steps, you can easily and effectively convert MBR disk to GPT disk without losing data. So that you can good manage you hard drive and take full use of disk space. AOMEI Partition Assistant is such a useful tool which can help resolve the problem “Convert to GPT greyed out server 2012” without data loss. It not only can convert MBR to GPT, but also can convert GPT to MBR. If you need convert disk between MBR and GPT partition styles in Windows 10/8/8.1/7, please turn to AOMEI Partition Assistant pro.