By Lucas / Last Updated March 4, 2022

Scenario: Can't format dynamic hard disk 

"Trying to add a second HDD to my friend's PC to give more storage. The HDD in question was previously the OS drive in an old PC and still has some windows and program files on it, I want to format but I can't format or delete the volume. And because it's a dynamic drive, most 3rd party software I found won't touch it. What can I do about this?"

About dynamic disk

Dynamic disk is an attribute of a disk, while our commonly used disk attribute is the basic disk. On basic disks, only continuous space on the same disk is allowed to be divided into one partition. But on the dynamic disk, there is no disk partition, it is named after "volume". There is a big gap between volume and partition: the same partition can only exist on one physical disk, while the same volume can span up to 32 physical disks. 

Differences between dynamic and basic disk

Therefore, the dynamic disk is a good choice in computer use due to its additional features such as creating volumes that span multiple disks, extending a simple or spanned volume, and accommodating RAID-5 volumes, and so on. However, some users still want to format a dynamic disk to a basic one. But when they open Disk Management, there's a greyed-out "Delete" or "Format" button in the right-click menu. 

The dynamic disk doesn't allow users to format it and users could only delete the spanned volume. Thus, users who wish to use a basic disk could only do a conversion to change the dynamic disk to a basic disk.

Possible reasons for users to convert dynamic disk to basic disk:

1. They've converted it to dynamic accidentally.

2. Convert to dynamic disk automatically when creating a primary partition in the condition that there are already 4 primary partitions on an MBR disk.

3. User convert a basic disk to dynamic is to break the MBR disk capacity limitation of 2TB. However, there is a GPT disk to help users handle large-capacity disks well. Users can convert MBR to GPT disk to fix this issue. So there's no need to use a dynamic disk.

Besides, according to Microsoft, the dynamic disks have been deprecated from Windows, so it is not suggested to use them anymore if you are not familiar with that type of disk.

How to convert dynamic disk to basic

Windows brings you ways to convert a dynamic disk. In general, you can do the conversion of dynamic to basic in Disk Management and Command Prompt. Let’s learn the detailed steps.

Note: these methods will cause data loss after formatting. Therefore, please back up all important files or backup dynamic volume in advance.

1. Delete volume in Disk Management

Step 1. Press Win + R to open Run. Type "diskmgmt.msc" and hit Enter to open Disk Management.

Step 2. Find the dynamic disk, right-click its volume and select "Delete Volume". Wait for the process completes. Repeat the step to delete all volumes on the dynamic disk.

Delete dynamic disk volume disk management

Step 3. Usually, the dynamic disk will become basic automatically after all volumes have been deleted. If not, right-click the dynamic disk after it becomes unallocated space and select "Convert to Basic Disk".

Tips: To convert mirrored volumes, you need to break mirrored volumes by Windows Disk Management.

2. Convert dynamic disk using CMD

Step 1. Click Start and type "Command Prompt" in the search box. Right-click the Command Prompt from the list and select "Run as administrator".

Step 2. At the prompt, type "diskpart" and press "Enter".

Step 3. Type following commands successively and press "Enter" after each input.

list disk
select disk n (where n is the disk number of the dynamic disk)
detail disk

Details dynamic disk CMD

select volume m (where m is the volume number of the dynamic disk)
delete volume
convert basic (run this after deleting all volumes on the dynamic disk)
exit (leave diskpart)
exit (leave command prompt)

Dynamic disk CMD

Tips: repeat “select volume m” and “delete volume” if you have more than one volume on the dynamic disk.

Some user tries to convert dynamic disk in Windows 7 install so that he can install Windows OS to a basic disk directly. To achieve that goal, these steps may be helpful.

Step 1. Boot the computer from the Windows installation disc. Follow the wizard to complete the first several settings.

Step 2. Stop when it comes to “Where do you want to install Windows?”. Then, press Shift + F10 to open a command prompt.

Step 3. In the command prompt, repeat step 2 - step 3 in the above method to convert dynamic disk to basic one.

Step 4. Leave the prompt and complete the installation with the wizard.

Convert dynamic drive to basic without data loss

With such easy ways provided, some users still find that dynamic drive cannot be converted in Windows. Normally, there are 3 situations:

◤ 1. The Delete Volume grayed out in Disk Management.
◤ 2. Windows returns the message: Windows cannot delete the system volume on this disk.
◤ 3. If run delete volume in Diskpart, this error message would appear: Virtual Disk Service Error: Delete is not allowed on the current boot, system, pagefile, crash dump, or hibernation volume.

The key problem is that they trying to convert a dynamic disk that contains system files, which is not allowed under the Windows environment. Users need to delete all data on the disk before they do the conversion on the disk with system files.

Is there any way to change dynamic disk to basic without losing any data? Fortunately, the answer is yes. AOMEI Partition Assistant Professional is very helpful in managing dynamic disks and dynamic volumes. It is with a built-in tool, Dynamic Disk Manager, allowing you to convert dynamic disk to basic disk without deleting volumes, regardless of system disk or data disk.

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Step 1. Install and run AOMEI Partition Assistant Professional. When there is a dynamic disk, click the Dynamic Disk button to launch "AOMEI Dynamic Disk Manager".

Dynamic disk Manager

Step 2. Then, Right-click the dynamic disk and select "Convert to Basic Disk".

Conver to basic disk

Step 3. Confirm the conversion by clicking "OK".

OK

Step 4. Click "Commit" in the toolbar to commit pending operations. And click "Proceed" in the pop-up window to start the process. Wait for the process completes.

Commit the conversion

Note: A reboot is required to convert the system dynamic disk to a basic disk.

Conclusion

Now you know what dynamic disk is, and three ways to convert a dynamic hard disk to basic, even without losing data on the system volume. Just choose the one that is the most suitable one for you. AOMEI Partition Assistant Professional can also help you manage dynamic volumes like move dynamic volume, resize volume, add drive to RAID, and so on. If you're a Windows Server user, please choose the Server edition of this convenient tool.