How to Resize Partition in Windows 10 without Losing Data?

If you cannot use Windows Disk Management change partition size in Windows 10, you can take use of the partition manager AOMEI Partition Assistant to resize Windows 10 partition more flexible.

December 23, 2014

How to Resize Partition in Windows 10 without Losing Data?

Partition is a part of a hard drive. Only after partitioning a hard drive, you can store data. Resizing a partition is to change the size of a partition by shrinking or extending it. And you can extend partition or shrink partition depending on your requirement. With the increasing data day after day, partition resize has become a common way used to partition management.

Why you should resize partition in Windows 10? The directly answer is that it can help you take full advantage of space. For instance, due to the daily increasing data, one or two of your partitions may be in low disk space, especially for system partition. At the same time, this problem will influence the speed of computer. How to solve the problem? The answer is resizing partition.

What’s more, if there is only a big partition on a hard drive when you buy a new computer. But as for most of users they require 2 or 3 partitions to store their files, applications and system separately. At this moment, you can resize partition to get unallocated space and then create partition within the unallocated space. You can also split partition to get multiple partitions.

Although Disk Management in Windows 10 can also help you extend or shrink partition, there are limitations for the tool. Take extending partition as an example, if there is no unallocated space next to the partition you try to extend, the Extend Volume will be grayed out so that you cannot extend volume in Windows 10. Meanwhile Disk Management cannot copy disk, copy partition, merge partitions, resize FAT partition and so on. So in this situation it is impossible for you to extend partition with this tool.

As for AOMEI Partition Assistant Standard, the free partition management software can enable you to resize partition, create partition, move partition, migrate OS to SSD and make bootable CD without losing any data.

Compared with Disk Management, this software allows you to extend partition without worrying if there is unallocated space next to the partition you want to extend. Besides, the more powerful features can help you manage your partitions completely.

The following steps will show the detail steps of how to resize partition.

Case1: Extend Partition

Before you do:

  • If the unallocated space is not adjacent to the partition you want to extend, you can move partition to adjust the position for the partition first.
  • If there is no unallocated space, you can shrink partition to get it at first.
  • Make sure there in no running program in the partition you want to resize.

Usually low disk space happens to system drive. So the following detail steps are how to resize system partition when there is unallocated space next to it.

Step1: Download AOMEI Partition Assistant Standard. After installing it, you can open it to resize partition in Windows 10 without data loss. Right-click C partition and then choose Resize Partition.

Step2: Right moves the bar to decide how much volume you want increase from the unallocated space and then click OK.

Step3: After step2, you will find the C partition is changed from 28.5GB to 54.54GB. To perform the operation, please click Apply.

Case 2:Shrink Partition

Step1: Open this software, right-click D partition and then choose Resize Partition.

Step2: Left drag the bar to change size of D partition to get unallocated space and then click OK.

Step3: You can see the size of D partition is smaller than before and there is unallocated space next to D partition. Click Apply to perform all the operations.


When you shrink partition, the operation will under PreOS Mode and your computer will reboot as the following situations:

  • The partition you want to shrink is system partition.
  • There is a page file or AOMEI Partition Assistant installation file in the partition which you try to shrink.
  • There are running programs in the shrinking partition.

AOMEI Partition Assistant Standard helps you resize partition within Windows 10 without losing any data. Besides using the feature of Resize Partition to expand partition, this software has another feature called Extend Partition Wizard which makes you increase the size of partition more easily.