By Emily / Last Updated October 11, 2019

Why need to split partition in Windows 10?

As its name suggests, splitting partition is to divide a large partition into two smaller partitions. It is quite necessary in some conditions.

For example, when there is only one partition (system C partition) on your new computer, and you have to store all data including OS, applications, personal files, etc in the same partition, the OS loading and running performance will be affected. Therefore, dividing it can make two partitions on the hard disk: one is for OS and another one is for personal files. Thereby, you’re your personal data can be safe during system crash and you can easily reinstall OS without damaging data in other partitions.

Besides, when one of your hard disk partitions is too big but just used a little, splitting it into two smaller ones enables you to store various data and make the fullest use of the disk space.

On the whole, splitting hard disk partition can make the partition number and size more reasonable.

How to split hard disk partition without formatting in Windows 10?

In general, in order to split one partition into two partitions, you can make use of Disk Management (Windows built-in tool) and AOMEI Partition Assistant Professional (3rd party software). In either way, you don’t need to format any partitions. Next, we will show how to split partition via those two methods.

Method 1. Use Windows 10 Disk Management to split partition

If you would like to apply Disk Management to separate a large partition, you need to first shrink a partition to get an unallocated space and then create a new partition on it.

Step 1. Right-click the bottom-left corner (or Start button) on the desktop to open “Quick Access Menu”, and then choose “Disk Management”. Or press “Windows+R” to open “Run”, type “diskmgmt.msc” in the empty box and tap “OK”.

Step 2. Right-click the large partition you want to shrink and select “Shrink Volume”.

Shrink Volume

Step 3. Then it will calculate how much space can be shrunken. In next window, you can input the shrunk size (MB) and click “Shrink” to proceed.

Enter Shrink Space

Step 4. Then you will see an unallocated space after the partition you shrunk. Now right-click it and select “New Simple Volume”, and then follow the wizard to create a new partition on the unallocated space.

Shrink Result

However, this way requires more than 5 steps and lots of time; moreover, it may lead to data loss. Luckily, there is an easier and safer way to split partition. Just keep reading!

Method 2. Use AOMEI Partition Assistant Professional to divide partition

In order to split a large partition into two smaller partitions without formatting or losing anything important, you had better use a third-party partition manager such as AOMEI Partition Assistant Professional.

It provides a specialized function for dividing hard disk partition called “Split Partition”, which can split hard disk partition into two just within 3 steps. Compared with Disk Management, it does not require you to shrink the partition first, so this method is more time-saving and safer.

Below we will take how to split system partition without formatting via this software as an example.

Note: Because only the partition with unused space can be split into two partitions, please make sure there is free space in the partition which you plan to divide.

Step 1. Install and run AOMEI Partition Assistant Professional. Right-click the C partition and select “Split Partition”.

C Drive Split

Step 2. In this window, you can specify the size and location of the new partition, and click “OK”.

Resize New Partition

Step 3. Back to the main interface, click “Apply” and “Proceed” to commit the pending operation.

Apply Split C Drive

● The splitting process will take some time, so allow your computer to finish this task before using it for anything else.
If there are 4 primary partitions on MBR disk and you plan to split one of them, the split partition will be converted to logical partition automatically.
● If there are four primary partitions on a hard disk, the program would not allow you to split the system partition or boot partition, unless you could convert one of the other partitions from primary to logical partition. The new generated partition will be automatically set as a logical partition.

In addition to splitting partition in Windows 10, AOMEI Partition Assistant Professional also offers many other amazing functions to help Windows users to resize hard disk partition without losing data, such as:

  • Merge partitions: this function will merge two adjacent partitions into one partition (opposite of splitting partition), or merge unallocated space into an existing partition to extend partition.

  • Move partition: it can change the location of one partition, through which you can change the location of the unallocated space as well, and then you can extend another partition.

  • Allocate Free Space: when you find one partition is too large while another partition is too small, you can use this feature to directly allocate free space from one partition to another partition.

  • Create Partition: this can not only create partition from unallocated space like Disk Management, but also allows you to create partition within existing partition.

Create Partition

Final words

Now, you must have learnt how to split partition in Windows 10 without formatting other partition using Disk Management and AOMEI Partition Assistant Professional. In consideration of convenience and data safety, AOMEI Partition Assistant is more recommended. If you want to split partition in Windows Server 2012/2016/2019 and so on, you can try AOMEI Partition Assistant Server.