Ways to Convert Partition Type, Partition Style, and Disk Type

The question how to change the type of hard disk partition is often asked on the internet, but many users haven’t found a good solution. Moreover, from the problem description I found many of them mix up concepts like partition type and partition style. For example, they say they want to change the partition type from MBR to GPT or from dynamic to basic. In this post, I will give a brief introduction to partition style, partition type, and disk type as well as show some ways to interchange these types or styles of disk and partitions to solve corresponding problems.

About Partition Style (MBR and GPT)

A brand new hard disk cannot be used to save data directly and we have to initialize it to either MBR (master boot record) or GPT (GUID partition table), and this operation can be completed in Windows Disk Management tool. Even if partitions have been created, we have chance to interchange them. Actually, we can say MBR and GPT are 2 kinds of partition styles. The former uses the standard BIOS partition table while the latter uses unified extensible firmware interface. On a MBR disk, we can create 4 primary partitions or 3 primary partitions and 1 extended partition at most, but on a GPT disk we can create up to 128 partitions. What’s the reason?

a MBR partition table is allocated with 64 bytes space only, and the entry of each primary partition takes up 16 bytes. That is to say the partition table can only hold 4 entries. Therefore, a MBR-formatted hard disk supports 4 primary partitions at most. More information can be found from master boot record in Wikipedia.

The partition table header on a GPT disk defines the number and size of the partition entries that make up the partition table. EFI requires the minimum of 16,384 bytes for partition table, so there are 128 entries, and each entry takes up 128 bytes. Therefore, we can create 128 partitions on GPT disks. In addition, booting Windows from GPT disk requires EFI firmware. If there is no such support, we may face boot failure. For detailed information about GPT partition style, please see GUID Partition Table of Wikipedia.

Therefore, when we want to create more partitions but the MBR disk has contained the maximum number of primary partitions, to convert the disk from MBR to GPT partition style is a good solution. Moreover, if Windows cannot be installed to GPT style partition since there is no EFI firmware support, changing the disk from GPT partition style to MBR is a good choice. In addition, converting MBR disk to GPT disk is a good solution to getting large-capacity hard disk support. Since the maximum addressable space MBR partition table supports is 2TB, space over 2TB on a MBR disk cannot be used. However, a GPT disk can recognize up to 18EB space.

How to Change Partition Style between MBR and GPT

For a never-used hard disk, we can do initializing in Windows Disk Management utility with ease. Detailed steps:
Right click the “Computer” icon on the desktop, choose “Manage” from the popup menu, and click “Disk Management” from the left side. After these operations, a initializing message will appear, and we only need to tap on the corresponding button.



For a disk where partitions have been created, we can convert partition style in the following 3 ways:
1.In Disk Management utility: backup all needed data, delete all existing partitions, right click the disk you want to convert, and choose the corresponding function from the popup menu. For example, if you want to convert the disk to GPT partition style, choose “Convert to GPT Disk”; if you want to convert the disk to MBR partition style, choose “Convert to MBR Disk”.



2.In Diskpart: backup all needed data in advance, run diskpart as administrator, and then type the following commands: list disk → select disk [disk number] → clean → convert GPT (or MBR) →exit.
Note: the clean command will delete all partitions on the selected disk.



After these commands are completed, our disk will be converted to the needed partition style. However, both ways require us to delete all partitions in advance, so next we will introduce a lossless way.
3.Use third party partitioning tool (take MiniTool Partition Wizard for example): select the disk we want to convert, then choose the corresponding function from the left side, and finally click “Apply” to make all changes performed. For detailed steps, please see convert MBR disk to GPT partition style disk or convert GPT disk to MBR disk.

Note: changing the disk which saves Windows OS to GPT may lead to boot failure, because booting Windows from MBR disk employs Legacy BIOS mode while booting from GPT disk employs UEFI mode. Moreover, the Windows 32 bit OS can not be installed on a GPT disk.

Note: what we change here is partition style, and next we will introduce different types of partitions.

About Partition Type (Primary and Extended Partition)

There are 3 types of partitions, including primary partition, extended partition, and logical partitions, which can be created in Disk Management utility after we initialize the hard disk to MBR. Next, let’s see main features of these 3 types of partitions:
Primary partition: on a MBR disk we can create 4 primary partitions or alternative 3 primary partitions and 1 extended partition at most. Windows boot files like bootmgr and ntldr should be saved in primary partition. Moreover, among these 3 types of partitions, only primary partition can be set active.
Extend partition: an extended partition is a special primary partition which makes it possible to create more than 4 partitions on a MBR disk. Actually, it is more like a range rather than a real partition, because we cannot save data to it directly and have to create logical partitions. A hard disk can hold only one extended partition.
Logical partition: logical partitions should be created in extended partition, and one extended partition can hold lots of logical partitions.

Since different types of partitions have different features, we can or need to change partition type to solve some problems. Next, let’s see 3 examples:
1.If we want to create more partitions on a MBR disk which has contained 4 primary partitions, we can set one of primary partitions to extended or logical to fix the issue since an extended partition can hold lots of logical partitions.
2.When there are 3 primary partitions and 1 extended partition already, creating new partition in unallocated space will convert the current disk to dynamic disk. If we want to create partition without converting the disk to dynamic disk, we can also convert one of primary partitions to logical to solve the problem.
3.Since Windows boot files can only reside in primary partition (main reasons will be listed in the following content), we may fail to install Windows in a logical partition. At this time, to convert the logical partition to primary is a good solution.

Well then, how to complete partition type conversion?

How to Change Partition Type between Primary and Logical Partition

To do the conversion in Windows Disk Management utility, we should take these operations: backup needed data, delete the partition, and then recreate a partition and set it with the desired partition type.

Actually, there is a way to convert partition type without deleting any partition, but third party partitioning tool is needed. The freeware MiniTool Partition Wizard is suggested. For detailed steps to convert primary partition logical, please see Set Partition as Logical. For steps to change logical partition to primary, please see Set Partition as Primary.

But when setting primary partition to logical, we should pay attention to the following 2 aspects:
1.Do not set the partition which saves Windows boot manager to logical (it is the system reserved partition. If there is no partition with such a name, it is the partition you install Windows to), because it may cause Windows unbootable. What’s the reason? To answer this question, we need to know parts of Windows boot process.

After BIOS completes a series of POST (power-on-self-test), it will pass boot control to MBR (master boot record). Then, MBR will check partition table to find the active partition where Windows boot manager (bootmgr.exe) is located, and boot manager finds and starts Winload.exe to load Windows OS. From the boot process we can find the item Active Partition. The partition saving Windows boot manager should be set active, because MBR can only give boot control to active partition. If not, Windows will be unbootable. In addition, only primary partition can be set active. If we set the partition saving Windows boot manager to logical, it cannot be set active. That is to say MBR will not deliver boot control to it. As a result, Windows cannot boot.

2.If there are 3 primary partitions and 1 extended partition already, we had better convert the primary partition neighboring to extended partition to logical. If we set another partition to logical, there will be 2 extended partitions, which is not allowed on a MBR disk.

After setting a primary partition to logical, we can shrink the logical partition to release free space which can be used to create new partitions. In Windows Vista and later Windows OS, we can shrink a partition in Disk Management utility. Detailed steps: right click the partition which needs shrinking, choose “Shrink Volume” feature from the popup menu, type space you want to shrink, and finally tap on “Shrink” button. Note: the partition you want to shrink should be formatted with NTFS. If it is FAT32, shrink it by using third party partitioning tool. However, if you are running Windows OS released before Windows Vista, third party partitioning tool is also needed, because disk utilities in these systems do not provide such a function. As to third party tools, you can also try MiniTool Partition Wizard. For detailed steps to shrink a partition, please see Move/Resize Partition. Moreover, if the logical partition does not have much unused space to shrink, we can extend it by taking free space from any other partitions on the same disk before shrinking. Please see Extend Partition to get details.

After seeing different types of partitions, let’s get to know what is disk type.

About Disk Type (Basic disk and Dynamic Disk)

Basic disk and dynamic disk are 2 types of hard disk configurations. A basic disk uses primary partition, extended partition, and logical partition to organize data while a dynamic disk employs dynamic volumes, including simple volume, mirrored volume, striped volume, spanned volume, and RAID 5 volume. Please see Dynamic Disk Volumes to get details of each kind of volume. For users who are employing dynamic disk, data integration and data security can be well ensured.

On a MBR-style basic disk, we can create 4 primary partitions or 3 primary partitions and 1 extended partition which supports up to 128 logical partitions, and on a GPT-style disk we can create 128 partitions. However, on a dynamic disk we can create approximately 2000 dynamic volumes.

Nevertheless, though there are many advantages to employ dynamic disk, limits still exist. Let’s see 3 examples:
1.Some Windows OS cannot be installed on dynamic disk, including Windows Vista Home Basic/Premium and Windows 7 Home Basic/Premium/Starter.
2.If we are running more than 1 operating system, we cannot boot Windows from any volume except the current one after converting a basic disk to dynamic disk.
3.On a dynamic disk we can only install Windows on the volume which was converted from a basic partition that retains an entry in partition table, and only volume converted from system partition or boot partition has an entry. Therefore, users often fail to install Windows on a dynamic disk.

Since different types of disks have different features, we sometimes need to convert disk type to solve some problems. Next, let’s see solutions.

How to Change Disk Type between Basic Disk and Dynamic disk

To convert a basic disk to dynamic disk, we can do it in Windows Disk Management utility. Steps are as follows:
Right click the target disk, choose “Convert to Dynamic Disk”, and click “OK” to start converting. All changes will be made automatically.



To convert a dynamic disk to basic disk in Disk Management tool, we need to take these steps:
backup all needed data and delete all existing volumes. When the last volume is deleted, the disk will become basic automatically.

However, users may meet the problem that it is impossible to delete the system volume or boot volume in Disk Management. At this time, you can resort to diskpart to delete the volume. Type these commands in diskpart:
list volume → select volume [partition number or drive letter] → delete volume override → exit.



From the introduction above we can see to convert dynamic disk to basic by using Windows built-in tool requires us to delete existing volumes, but actually you can do it without deleting any volume. That is to make use of third party partitioning tool, like MiniTool Partition Wizard. Please see Convert Dynamic Disk to Basic Disk to get both article help and video help.

Now most people would know what is partition style, partition type, and disk type as well as ways to interchange change them. I hope this post is useful for you.