Learn how to create more than 4 partitions on an MBR disk or create more than 4 primary partitions by converting to GPT disk in Windows 10/8/7.
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.
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.
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?
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.