About Primary Partition and Logical Partition
You can store your data on a hard disk only when you have partitioned the hard drive in Windows 10. There are different types of partitions such as
primary partition, logical partition and they are different from each other.
Primary partition
Primary partition is where operating system can be installed. Only the system is
installed on primary partition, can it boot normally. And the primary partition
where you install operating system will be marked as active partition which is used
for initial booting. Each primary partition has its own boot block.
Logical Partition
The number of logical partitions on a hard drive depends on the type of the disk.
There are 2 disk types: MBR and GPT. As for MBR disk, you are only allowed to create
4 primary partitions or 3 primary partitions plus 1 extend partition. The extend
partition isn’t to store data, but to create unlimited logical partitions. After
creating partition, you can store data on logical drive just like primary
partition.
Why Need to Convert Primary to Logical in Windows 10?
As mentioned above, MBR disk only supports 4 primary partitions or 3 primary
partitions plus 1 extended partition. If there have been 4 primary partitions on
your MBR disk, you can’t create other new partition due to the limitation of MBR.
But you hope to more partitions to store your data separately from other data, at
this moment, you need to convert to logical partition.
Although Windows 10 has been improved most compared with the early version, it still
doesn’t allow you to convert primary to logical with Disk Management or DiskPart.
What can you do to solve the problem?
Convert Primary to Logical in Windows 10 with AOMEI Partition Assistant
Professional
AOMEI Partition Assistant Professional is a third-party software devoted to partition management. It
allows you to convert primary drive to logical in Windows 10 easily. Besides this
feature, it can also help you allocate free space, migrate OS to SSD,
make conversion between MBR and GPT The following will show you the detail steps of
how to convert primary partition to logical partition in Windows 10?
Step1: Install and launch
the software. Right click the partition you need to convert (eg. partition D) and
then choose “Advanced” and then select “Convert to Logical.”

Step2: Click OK to continue.

Step3: Click Apply to perform the operation.

Note:
Convert primary partition to logical is mainly used on basic MBR disk.
You’re not allowed to convert a boot partition to logical. Otherwise, you
computer will likely to stop working.
The location and the size of the primary partition will be slightly changed
after converting since the logical partition is 63 sectors bigger than primary
partition.