By Ailsa / Last Updated September 9, 2019

The problem

There is a user who has this problem too, like he said: I have a new 4TB external hard drive and tried to make a bootable drive. However, I see there are two parts as unallocated space, each partition is about 2TB, and I can only access the 2TB of it. The option is create a new partition or format volume is grayed out when right click the 2nd partition. I know there is nothing wrong with my external hard drive. Now I just want to merge the two partitions as one. So I run DiskPart command (format fs=ntfs quick label=data) to format but I get an error “Virtual Disk Service Error: the volume is not formattable”.

The reason

Now, we can analyze the reason why it shows virtual disk service error after DiskPart command prompt in Windows 7/8/10. The most possible reason would be the MBR partititon style if the external hard drive has no problem. As we all know, partition style contains MBR (Master Boot Record) and GPT (GUID Partition Table). The user used a MBR hard drive, which the capacity is up to 2TB while the GPT supports 256TB. Thus, the remaining space cannot be accessed or formattable when the partition style is MBR in the drive.

The solutions

Best way to fix/repair virtual disk service error the volume is not formattable

The problem is easy to solve, you can convert MBR to GPT without losing data to fix the DiskPart the volume is not formattable error with the best disk partition manager-AOMEI Partition Assistant Standard in Windows 7/8/10, now you can download this magic conversion tool. Compared with DiskPart and Disk Management, this software is better by one tally. You have to backup data when you use the DiskPart or Disk Management due to the data loss of the conversion.

To solve the Virtual disk service error the volume is not formattable error, the simple steps as follows:

1. Execute the program, right click the hard drive you want to operate on the main window, choose Convert to GPT Disk.

Convert 3tb Disk To Gpt

2.Tick OK to confirm converting MBR to GPT without losing data.

Ok 3tb

3.Click Apply to repair the Virtual disk service error the volume is not formattable issue.

Apply 3tb

After this operation, the virtual disk service error will be solved. Then you could merge two partitions, resize partition to increase or reduce partition size, migrate OS to SSD, etc.

Tips: You might try AOMEI Partition Assistant Professional to convert system disk from MBR to GPT or vice versa. The Standard edition is capable of converting between MBR and GPT on data disk.

Besides, you could try to make bootable media with this partition manager after converting, here is the tip:

  1. Prepare a USB flash drive at least 16GB or external hard drive, connect with the computer.

  2. Open AOMEI Partition Assistant Standard, choose Make Bootable Media under Wizards.

Make Bootable Media

Warning:

l The DiskPart command and Disk Management will damage your crucial data while fixing the Virtual disk error the volume is not formattable problem, please backup data before you converting.

l You have to make sure that the motherboard support EFI/UEFI boot mode. It cannot boot the operating system on GPT hard drive if the motherboard only supports BIOS boot mode.

DiskPart command

1. Type diskpart in search box on the desk.

2. Input list disk.

3. Type select disk [disknumber].

4. Input clean to delete partitions on MBR disk.

5. Input convert gpt.

DiskPart

Disk Management

Right click This PC->manage->Disk Management, then convert MBR to GPT. Make sure you have backup the critical information. If your disk has partitions, please delete all of it and then convert MBR to GPT without losing data.

Further ReadingOther virtual disk service errors

What is the Virtual disk service means. The Virtual disk service (VDS) is a set of application programming interfaces (APIs) that provides a single interface for managing your storage devices such as creating or deleting, formatting volumes, assigning drive letters to volumes and converting basic disk into dynamic disk and so on. It is supported on Windows server 2003, Windows Vista and later. The components working with virtual disk service include the Disk Management snap-in, the DiskPart command-line tool, and the DiskRAID command-line tool (Diskraid.exe). Thus, you may meet the problem “Virtual Disk Service Error: the volume is not formattable” when you format the volume.