By Emily / Last Updated September 30, 2021

The Symptoms

If you have a drive larger than 2TBs then you may find that Windows 11/10 DiskPart is unable to extend the partitions beyond 2TBs. If this is the case, you will likely receive the below Virtual Disk Service error:

“Only the first 2TB are usable on large MBR disks. Cannot create partitions beyond the 2TB mark, nor convert the disk to dynamic.”

Service Error

Or another reason it fails is that:

“The volume cannot be extended because the file system does not support it.”

The Cause

Luckily, the problem is clearly stated in the error message that DiskPart displays. MBR (Master Boot Record) only supports a maximum disk size of 2TBs and four primary partitions (or 3 primary and one logical partition). This means that any storage space beyond 2TBs will be unusable by Windows if the disk is MBR formatted. In order to solve this, you can convert the disk to the GPT (GUID Partition Table) style as it is able to utilize disks larger than 2TBs.

Additionally, the FAT32 file system also limits the maximum partition size of a disk to 2TBs, so if your disk is in the GPT style but formatted in FAT32 then you will also be unable to use DiskPart to extend your partitions beyond 2TBs. Fortunately, Microsoft first introduced an alternative to FAT32 in 1993, the alternative file system, NTFS allows you to create much larger partitions than FAT32 traditionally allows.

Solution 1: convert MBR to GPT disk without data loss

Solution 1: convert MBR to GPT disk without losing data

If you have discovered that your hard drive is in the MBR format then you can use specialist freeware to convert it to GPT without losing data or formatting your drive. AOMEI Partition Assistant Standard edition, a free partition manager, converts your disk to GPT without impacting any of the data. If you want to convert your system disk then you will need AOMEI Partition Assistant Professional edition and you will need to check whether your motherboard supports EFI/UEFI boot mode.

Let’s find out how it works:

1. Download the free software. Install and launch it.

2. Right click the disk you want to convert and select ‘Convert to GPT’.

Convert MBR to GPT

3. Click Apply to perform the operation.

Convert to GPT

Apply Convert MBR to GPT

Once the conversion has completed, you should be able to extend your partitions beyond 2TB limit by using AOMEI Partition Assistant, you can now also use DiskPart to extend partitions.

If you want to use DiskPart to convert MBR to GPT then you can use the command “convert gpt”. Remember, this command will only work when the disk is completely empty and doesn’t contain any data partitions or volumes. You can use the “delete disk [noerr][override]” command to delete the disk before converting it to GPT. The built-in Windows Disk Management utility can also be used to convert a completely empty disk (which shows up as unallocated space) to GPT. As using Diskpart and Disk Management requires you to erase the hard drive, remember to backup your hard drive before trying.

Note: this only works with 64 bit OS’s.

Solution 2: convert FAT32 to NTFS without losing data

If you still can’t extend your 2TB partition after converting the disk to GPT, then you will need to check what file system your drive is using. If it is in FAT32 you will need to convert it to NTFS. Typically you will need to reformat the partition or volume to this, which involves deleting all of the data. Fortunately, AOMEI Partition Assistant Pro is able to convert between FAT32 and NTFS without reformatting the drive and losing your data.

To convert from FAT32 to NTFS:

1. Download AOMEI Partition Assistant Pro Demo Version and run it. Click on All Tools then NTFS to FAT32 Converter.

NTFS to FAT32 Converter

2. Select FAT32 to NTFS.


3. The program will list the partitions formatted with FAT32. Select the partition you want to convert and click Next and then Proceed to start the conversion.

FAT32 Partitions

Proceed FAT32 to NTFS

After trying these two solutions you should find that DiskPart is be able to extend your partition to larger than 2TBs. AOMEI Partition Assistant isn’t just a powerful partition manager, it has a whole host of useful features that can be used to make bootable media, Migrate your OS to an SSD, resize partitions, and more! AOMEI Partition Assistant is compatible with a range of operating systems both for the home (Windows 11, 10, 8.1/8, 7, Vista, and XP) and for businesses (Windows Server 2012, 2008 (R2), 2008, and 2003).