Background
Have you ever received a warning that the operation you selected will convert the
selected basic disk to dynamic
disk or the New Simple Volume option is grayed out while trying to create a
new partition with Disk Management? It seems that Disk Management does not allow you
to create more than 4 partitions unless you convert the disk to dynamic. Is it true?

To completely understand and work this around, you need to learn the basic limits of
Master Boot Record (MBR) partition style. Long story short, when you initialize a
new disk, Windows will ask to select the partition style, MBR or GUID partition
table (GPT). MBR disks have some basic limits that it can contain at most 4 primary
partitions or less than 4 primary partition and many logical partitions, and MBR
disk space beyond 2 TB becomes unusable.
By default, Windows will select MBR, possibly because any version of Windows
operating system (OS) can be installed on an MBR disk, but GPT disk only supports
64-bit version of Windows 7 and the latter Windows OS, though GPT disks do not have
such restrictions. Therefore, if you want to have more than 4 partitions on hard
drive with MBR partition style without converting to dynamic disk, you need to
convert at least one existing primary partition to logical partition, and then you
can create more partitions as logical drives.
Create more than 4 partitions by converting a primary partition to logical
partition
The Windows built-in utility - Disk Management does not allow you to specify a
primary or logical partition when creating a new one, instead it will create primary
partitions by default. If you don’t select all the unallocated space to create the
fourth partition, namely leaving some unallocated space out of the 4 partitions, the
fourth partition will be created as logical partition, giving you the choice to
create more logical drives. If you already have 4 primary partitions on a MBR disk,
that is you cannot create new partition with Disk Management, you can use the
following steps to work this around:
1. With Disk Management open, click on one existing primary partition and select
Delete Volume. This will delete data on the selected partition, backup
the important data beforehand.

2. Right click on the unallocated space and select New Simple Volume.

3. Follow the New Simple Volume Wizard to create a new partition. Make sure there is
enough unallocated space to create a new partition when specifying volume size.

4. Then it will create a logical partition as the next partition to be created.

Of course, you can also use Diskpart.exe to delete partition and create logical
partition from command line. Actually, instead of using this complicated method and
losing all the data on the primary partition deleted, you can also use third party
free partition manager software - AOMEI
Partition Assistant Standard to create partitions directly on a MBR disk,
though it already has 4 primary partitions.
Create new partitions with AOMEI Partition Assistant
Step1: Download, install and
launch the software. In this example, you can find there are already 4 primary
partitions on MBR Disk 1. Right click on the unallocated space and select Create
Partition. If no unallocated space, you can also click on an existing
partition as long as there is free space on the partition.

Step2: On the pop-out window, drag the slider to or enter an amount
of space adjust size of the partition to be created. You can also click Advanced
to see more options such as drive letter, file system, etc.

Step3: After clicking OK, you can see the last partition and the new
created one becomes logical partitions automatically. If no problem, click Apply
to execute this operation.

That is it. In seconds, a fifth partition will be created, and then you can create as
many logical partitions as you like. You may want more primary partitions to install
other OSes or some other reasons, so how to create more than 4 primary
partitions?
Create more than 4 primary partitions without losing data
As mentioned, a MBR disk can only have 4 primary partitions, so you need to convert
disk to GPT before you can create more primary partitions. The Windows built-in tool
- Disk Management and Diskpart.exe can only convert an empty disk without any
volumes or partitions from MBR to GPT, which is why the Convert to GPT option is
grayed out in Disk Management. Luckily, the partition manager software, AOMEI
Partition Assistant also enables you to convert MBR to
GPT without data loss.
Before the conversion, make sure that your computer supports unified extensible
firmware interface (UEFI) boot mode if you are planning to convert a system disk to
GPT, which requires AOMEI
Partition Assistant Professional for PCs or AOMEI Partition
Assisntant Server for servers. If it is system disk you are converting, this
process will be complete in AOMEI PreOS mode. When it is done, boot into BIOS to
enable UEFI mode, and then you can create more than 4 primary partitions
effortlessly with AOMEI Partition Assistant. Besides, AOMEI Partition Assistant Pro
can also be used to migrate OS to SSD, convert NTFS to FAT32, convert dynamic disk to basic
without data loss, and more.