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  3. How to Resize Partition with AOMEI Partition Assistant?
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Get Started
Basic Partition Options
Basic Disk Operations
Change Partition Size
Clone
Partition Converter
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Partition/Data Recover
Wipe Partition/Disk
Disk Test
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FAQ and Error Codes

How to Resize Partition with AOMEI Partition Assistant?

What is partition resizing? How to resize a partition? Resizing partition includes extending partition and shrinking partition. With the help of AOMEI Partition Assistant you could resize partition accurately and easily.

AOMEI Post By AOMEI Updated June 19, 2025

Overview of Resize Partition

Resizing partition means changing the size of a partition on a hard drive as you like, either extending it or shrinking it. But when you shrink a partition, you can at most shrink it to the size of its used space, so that you can use the partitions with more flexibility. For example, you can store applications or files on any one of the partitions. If the partition is running out of space, you can extend it with the space shrunk from other partitions on the drive. Besides, you can create new partitions with the room from other partitions.

Here are several situations in which you would like to resize partition

When you buy a new laptop or PC, it may have been pre-installed with a system and come with a big C drive but small data partitions, or a small C drive but large data partitions. No matter which one it is, you will find it hard to make full use of the whole disk space.
When the computer has been used for a long time, you may have encountered the message: the system drive is running out of space.
If the Windows 10 upgrade failed with the error "Couldn't update system reserved partition", the most likely cause is that the system reserved partition is too small. Then you can extend the system reserved partition.

For example, once when I was downloading a player online, following the installation steps without setting the destination, a message came saying that my C disk does not have enough space to install the application. Thus, I have to either reset the destination or give up my intention. Therefore, later, I set the D or F partition as the destination to avoid such a problem, following the advice of my friends.

I know I can extend my C drive with Windows' self-contained function, but I didn’t know how because it seems very difficult. Being neither a computer professional nor a computer lover, I’ve usually been caught by problems. It is extremely annoying! But now, I’m not troubled by such problems anymore with AOMEI Partition Assistant. It helps me manage my disks very well with its intuitive interface and simple steps. By the way, it is compatible with Windows 11, Windows 10, Windows 8/8.1, and Windows 7.

How to resize partition with Partition Assistant

Before you do

  • Download and install AOMEI Partition Assistant on a Windows computer.
  • Check the partitions you want to resize and make sure there is no error.
  • To resize a partition, there must be enough free space on the same drive.
  • Do not forcibly terminate the tasks or cut off the power; otherwise, you might lose your data.
  • Close all running applications on the partitions you want to resize.
  • For more detailed information, you could view the tutorial "How to Safely Partition?"

Case 1: Extend Partition

To extend partition means to increase the partition size. Please note the two points below:
There must be an unallocated space on the same hard disk where the partition to be expanded is located. If there's no unallocated space, you could shrink other partitions on the same drive to generate the unallocated space.
The unallocated space should be adjacent to the partition you want to extend, no matter it is in front of the target partition or behind it. If not, you could use the feature "Move Partition" to adjust its position.

Step 1: Select a partition to Resize/Move Partition 

Install and launch AOMEI Partition Assistant. In the main console, you could view the whole partition configuration. In this demonstrator, there is an unallocated space behind the C drive. Then, right-click the partition (here is the C: partition) you want to extend and select "Resize /Move Partition".

Resize C Drive

Step 2: Manually extend the partition

In the pop-up window, position the mouse pointer on the right border of the partition and drag the border rightwards to extend the partition. Then click "OK". (If there's no unallocated space beside the partition, you cannot drag the border).

Extend C Drive

Tips:
  • There is an option "Using new mode to resize/move partition in the fastest and safest way.". If you tick this option, it will be safer and faster to resize your partitions, especially for NTFS partitions. Once this option is checked, the data will be intact even if the software ends abruptly or is cancelled during the operation.
  • If there is no enough space on the C drive, you can use the "App Mover" tool to move programs and folders to another external drive to free up your drive space.

Step 3: Apply to proceed

You can preview the expand operation by viewing the "Pending Operations". To commit the "Pending Operations", please click "Apply" and "Proceed".

Apply Extend C Partition

Tips:

Step 4: Extend successfully

Wait for the operation to be finished. After it is completed successfully, you will find the C: partition has been expanded.

Expand Result

Case 2: Shrink Partition

Shrinking partition could help you release some unused space from one partition and get some unallocated space. After that, you could make new partitions and/or increase other partitions with the unallocated space.

Step 1: Select a partition to Resize/Move Partition

1. Install and launch AOMEI Partition Assistant. In the main console, you could view the whole partition configuration. Then, right-click the partition (here is D:) which you want to shrink and select "Resize/Move Partition".

Resize D Partition

Step 2: Manually shrink the partition

In the pop-up window, position the mouse pointer on either border of the partition and drag the border rightwards or leftwards to shrink the partition. Then click "OK".

Shrink D Partition

Step 3: Apply to proceed

You can preview the shrink operation by viewing the "Pending Operations". To commit the "Pending Operations", please click "Apply" and "Proceed".

Apply Shrink D Partition

Step 4: Shrink successfully

Wait for the operation to be finished. After it is completed successfully, you will find the D: partition has been shrunk.

Shrink Result

 

Conclusion

Following the above steps, your partitions will be expanded or shrunk successfully. It is a very useful tool to help you manage your disk space in an easier and faster way.

This feature is usually used to expand partitions if one partition has run out of space while there is more free space on other partitions or unallocated space on the drive. For instance, this feature helps you extend your system partition if your computer gets a message of insufficient space.

Furthermore, Partition Assistant also provides more wizards to help you quickly adjust partitions, such as allocate free space, or expand partition wizard, etc.

 

Notes:
  • The partition shrinking operation will be performed under PreOS Mode, and your computer will reboot when:
           Shrink the system and/or boot partition.
           Shrink a partition on which the page file or the AOMEI Partition Assistant installation file is on.
           Shrink a partition where applications are running. AOMEI Partition Assistant will suggest that you close them or perform partition shrinking operations under PreOS Mode.
  • For a BitLocker BitLocker-encrypted partition, Partition Assistant will first decrypt the BitLocker encryption in advance.
 

FAQs

Q: Why is the option "Resize Partition" greyed out?

A: For ReFS, ExT2/3, ExFAT file systems, and other unknown file systems, it is unable to resize. AOMEI Partition Assistant only supports the format, delete, and wipe operations.

Q: Is it possible to resize the exFAT partition?

A: Currently, it is unable to resize the exFAT partition.

Q: How long will it take to resize a partition?

A: It depends on the amount of data. The program will also prompt for an estimated time after clicking the "Apply" button.

Q: Is it possible to use the feature "Resize Partition" to extend a partition with space from another hard disk?

A: No, currently, you can only use the feature to extend a partition with space on the same disk.

 
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