By AOMEI / Last Updated May 15, 2020

The Problem

While trying to shrink a volume with Disk Management or Diskpart in Windows 10/8/7/Vista/2008/2012, you may receive an error saying access is denied. Why did this shrink volume access denied error happen? How can it be sold out?

Access Denied

The Cause

The user account used to log in does not have the permission to access this partition as the error suggests. This error also happens usually when Another Windows operating system was installed on the selected partition to be shrunk. If there are unmovable files located on the end of this partition, you cannot shrink volume.

The Solution

To solve this problem, you may try one or more steps listed below based on your own situation.

1. Log in with administrator account and turn off UAC.

2. Right-click Drive and go Properties > Security > Edit to see if "Administrators" is included in the "Group and user names. If it is not, click the Add option to add Administrators group into this name list.


3. Boot into Windows Safe Mode to see if shrink volume works.

4. Disable hibernation and system protection temporarily.

5. Use Disk Cleanup to delete all system files stored on the partition that you want to shrink.

6. Run Defragment.


7. If all these moves, and you still get an error disk logical error access denied or something like that, you can try third party free partition manager software to shrink volume, because third party tools, unlike built-in utilities, does not have these restrictions regarding disk management.

Shrink partition with free partition manager

The freeware for Windows 10/8/8.1/7/XP/Vista, AOMEI Partition Assistant Standard allows you to shrink a partition without restrictions, regardless of the unmovable files. Therefore, it can avoid the access denied problem when trying to shrink volume. Let’s see how it goes with shrinking volume:

1. Download, install and launch the freeware.

2. Right click on the partition you want to shrink and choose "Resize Partition".

Resize Partition

3. In the next screen, you can enter the new size of the partition or drag the slider leftwards to shrink the partition. If you want to specify the new location for the partition, you can drag the partition.

Shrink Partition

4. At this stage, the program has done nothing to your disk, but allows you to preview the partition layout after the operation. If it is not what you want exactly, you can easily undo the operation and modify it. Till it meets your needs, click Apply to put the operation in process.


If you want to use the unallocated space created by shrinking volume, you can add it to one of the other existing partitions using merge partitions or create a new partition. With AOMEI Partition Assistant, you will never have the shrink volume access denied problem. Besides, this software can also be used to convert dynamic disk to basic disk without data loss,quickly partition hard drive, migrate OS from GPT disk to MBR SSD drive, and many more. If you upgrade to AOMEI Partition Assistant Professional, you can use Allocate Free Space feature to directly move free space from one partition to another without shrinking partition