How to Adjust/Change Partition Size Without Losing Data in Windows 10/8/7?

April 2, 2019

In this article, we will show you how to change partition size without losing data in Windows 10/8/7 computer no matter whether you want to increase or decrease the partition size.

Main reasons for changing partition size

Resizing partitions is to change the size of a partition as you need, either extending to make it bigger or shrinking to make it smaller. Users might need to resize partition without losing data for different reasons such as:

> Partition is running out of space: As time goes by, you store lots of data to your partitions and the drive is running out of space gradually. Besides deleting unnecessary data from it to free up disk space, you can also resize partition to make it bigger by getting some free space from other larger partitions on the same disk.

> Partition size is not reasonable: Too many partitions exist on the disk, but some of them are too large in size, and others are too small in size. You might need to resize those partitions to make them reasonable.

> Create new partition: When you need to create a new partition, you always need to first get an unallocated space by shrinking a certain partition.

> Add unallocated partition: After you clone disk to larger disk, or convert over 2TB MBR disk into GPT, there will be an unallocated space at the end of the disk. Then you can add the space into existing partition through adjusting partition.

2 methods to change partition size without losing data

Now, we would like to share 2 methods to free adjust partition on Windows 10/8/7 without data loss no matter you are planning to shrink or enlarge partition size.

Method 1. Windows native Disk Management(Restricted)

Windows Disk Management comes with “Shrink Volume” and “Extend Volume” functions. Both of them are safe and free to change partition size without losing data in Windows 10/8/7. To perform such tasks via Disk Management tool, first open it: right click “This PC/My computer”, select “Manage”, and click “Disk Management” under “Storage” in the left panel. Then you can get information on all your disk partitions.

  • To decrease partition size

Step 1. Right click the partition you want to resize and click “Shrink Volume”.

Shrink Volume

Step 2. In the pop-out window, you can enter the specific amount of space to shrink and click “Shrink” to execute the operation.

Enter Shrink Space

Step 3. In a while, this selected partition will be shrunken to be smaller.You will see an unallocated space on the right side of the shrunken partition.

Shrink Result


>>You can only shrink NTFS partitions, but it is impossible to shrink FAT32 and other types of partitions.

>> The generated unallocated space will be and only be located on the right side of the original partition.

  • To increase partition size

Step 1. Right click the target partition and choose “Extend Volume”.

Extend Volume

Step 2. Then the “Extend Volume Wizard” will appear, you can set and add more size to your target partition and click “Next” to continue.

Select Unallocated Space

Step 3. Follow the guidelines to accomplish the process.



>>The “Extend Volume” option will be clickable only when there is adjacent unallocated space on the right side of the partition you want to extend. Otherwise, the Extend Volume will grey out.

>>You can only extend NTFS partition.

Method 2. Third-party partition software (More powerful)

Because of the limitations listed above, Windows Disk Management might be not the best tool to change partition size without losing data. Thus, you can use AOMEI Partition Assistant. This freeware is a much more powerful tool for Windows 10/8/7/XP/Vista (32 & 64 bit). Compared with Disk Management, AOMEI Partition Assistant has many advantages while adjusting partition size including:

>> Support moving partition during resizing partition, so the unallocated space can be generated on either side when shrinking a partition.

>> Both NTFS and FAT32 partition are supported to resize (shrink or extend).

>> Support partition alignment for SSD drive when necessary, which can help optimize SSD performance to some degrees.

>> Nonadjacent unallocated space can be easily merged or combined to other partitions in the same disk.

Download the freeware, install and launch it on your Window PC, then you’ll see all connected storage device with overall partition layout.

  • To shrink partition:

Step 1. Right click the partition needing to be shrunk (here we select D partition)and select “Resize Partition”.

Shrink D Drive

Step 2. In this window, drag slider bar on both sides to shrink it. Or you can move the partition location by dragging it rightward when the mouse becomes a cross crux.

Drag To The Left Shrink

Step 3. In the main interface, click “Apply” and then “Proceed” to execute the pending operation.

Proceed Resize Shrink

  • To extend partition:

If there is unallocated space on the same disk no matter it isadjacent or nonadjacent to the partition you want to extend, you can directly adopt “Merge Partition” function to combine it into the target partition. If there is not, you can first shrink another partition to get an unallocated space (like we demonstrate in the “shrink” section). Next is how to merge unallocated space into partitions.

Step 1. Right click the partition you want to enlarge (here we select C partition), and click “Merge Partition”.

Merge Partitions C

Step 2. Here, you can tick an unallocated space to merge to C partition. 

Merge C And Unallocated Space

Step 3. Click “Apply” to commit the pending operation.

Apply Merge C And Unallocated Space

Besides merging unallocated space into one partition on the same disk, it also supports merging two adjacent partitions into one (PS. System partition cannot be merged into data partition). If you upgrade to AOMEI Partition Assistant Professional, you can even allocate free space from one partition to another to change partition size without losing data.